Accessories with magnetic alignment components

ABSTRACT

A magnetic alignment system can include a primary annular magnetic alignment component and a secondary annular magnetic alignment component. The primary alignment component can include an inner annular region having a first magnetic orientation, an outer annular region having a second magnetic orientation opposite to the first magnetic orientation, and a non-magnetized central annular region disposed between the primary inner annular region and the primary outer annular region. The secondary alignment component can have a magnetic orientation with a radial component.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/028,275, filed Sep. 22, 2020, which claims the benefit of U.S.Provisional Application No. 62/907,332, filed Sep. 27, 2019, and of U.S.Provisional Application No. 63/061,752, filed Aug. 5, 2020. Thedisclosures of each of these applications are incorporated by referenceherein for all purposes.

The following U.S. patent applications filed on Sep. 22, 2020, alsoclaim the benefit of the above-referenced provisional applications: U.S.patent application Ser. Nos. 17/028,231, 17/028,256, 17/028,295 (nowU.S. Pat. No. 11,342,800), Ser. Nos. 17/028,310, and 17/028,325.

BACKGROUND

The present disclosure relates generally to consumer electronic devicesand more particularly to magnetic alignment components and systems thatfacilitate establishing and maintaining a desired alignment between two(or more) devices, e.g., for purposes of enabling efficient wirelesspower transfer between the devices.

Portable electronic devices (e.g., mobile phones, media players,electronic watches, and the like) operate when there is charge stored intheir batteries. Some portable electronic devices include a rechargeablebattery that can be recharged by coupling the portable electronic deviceto a power source through a physical connection, such as through acharging cord. Using a charging cord to charge a battery in a portableelectronic device, however, requires the portable electronic device tobe physically tethered to a power outlet. Additionally, using a chargingcord requires the mobile device to have a connector, typically areceptacle connector, configured to mate with a connector, typically aplug connector, of the charging cord. The receptacle connector includesa cavity in the portable electronic device that provides an avenue viawhich dust and moisture can intrude and damage the device. Further, auser of the portable electronic device has to physically connect thecharging cable to the receptacle connector in order to charge thebattery.

To avoid such shortcomings, wireless charging technologies have beendeveloped that exploit electromagnetic induction to charge portableelectronic devices without the need for a charging cord. For example,some portable electronic devices can be recharged by merely resting thedevice on a charging surface of a wireless charger device. A transmittercoil disposed below the charging surface is driven with an alternatingcurrent that produces a time-varying magnetic flux that induces acurrent in a corresponding receiver coil in the portable electronicdevice. The induced current can be used by the portable electronicdevice to charge its internal battery. Some portable electronic deviceshave been designed to not only receive power wirelessly but also totransmit power wirelessly to other portable electronic devices, such asaccessory devices.

SUMMARY

Among other factors, the efficiency of wireless power transfer dependson the alignment between the transmitter and receiver coils. Forinstance, a transmitter coil and receiver coil may perform best whenthey are aligned coaxially. Where a portable electronic device has aflat surface with no guiding features, finding the proper alignment canbe difficult. Often, alignment is achieved by trial and error, with theuser shifting the relative positions of the device and charger andobserving the effect on charging performance. Establishing optimalalignment in this manner can be time-consuming. Further, the absence ofsurface features can make it difficult to maintain optimal alignment.For example, if the portable electronic device and/or charger arejostled during charging, they may be shifted out of alignment. For theseand other reasons, improved techniques for establishing and maintainingalignment between electronic devices would be desirable.

According to embodiments described herein, a portable electronic deviceand an accessory device can include complementary magnetic alignmentcomponents that facilitate alignment of the accessory device with theportable electronic device and/or attachment of the accessory device tothe portable electronic device. The magnetic alignment components caninclude annular magnetic alignment components that, in some embodiments,can surround inductive charging transmitter and receiver coils. In thenomenclature used herein, a “primary” annular magnetic alignmentcomponent refers to an annular magnetic alignment component used in awireless charger device or other terminal accessory. A “secondary”annular magnetic alignment component refers to an annular magneticalignment component used in a portable electronic device. An “auxiliary”annular magnetic alignment component refers to an annular magneticalignment component used in a charge-through accessory.

In some embodiments, a magnetic alignment system can also include arotational magnetic alignment component that facilitates aligning twodevices in a preferred rotational orientation. A rotational magneticalignment component can include, for example, one or more magnetsdisposed outboard of an annular alignment component. It should beunderstood that any device that has an annular alignment component mightor might not also have a rotational alignment component, and rotationalalignment components may be categorized as primary, secondary, orauxiliary depending on the type of device.

In some embodiments, magnetic alignment components can be fixed inposition within a device housing. Alternatively, any or all of themagnetic alignment components in a device (including annular and/orrotational alignment components) can be made movable in the axial and/orlateral direction. A movable magnetic alignment component can allow themagnets to be moved (e.g., axially) into closer proximity to increasemagnetic forces holding the devices in alignment or moved away from eachother to reduce the magnetic forces holding the devices in alignment.

The following detailed description, together with the accompanyingdrawings, will provide a better understanding of the nature andadvantages of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a simplified representation of a wireless charging systemincorporating a magnetic alignment system according to some embodiments.

FIG. 2A shows a perspective view of a magnetic alignment systemaccording to some embodiments, and FIG. 2B shows a cross-section throughthe magnetic alignment system of FIG. 2A.

FIG. 3A shows a perspective view of a magnetic alignment systemaccording to some embodiments, and FIG. 3B shows a cross-section throughthe magnetic alignment system of FIG. 3A.

FIG. 4 shows a simplified top-down view of a secondary alignmentcomponent according to some embodiments.

FIG. 5A shows a perspective view of a magnetic alignment systemaccording to some embodiments, and FIG. 5B shows an axial cross-sectionview through a portion of the system of FIG. 5A.

FIGS. 5C-5E show examples of arcuate magnets with radial magneticorientation according to some embodiments.

FIGS. 6A and 6B show graphs of force profiles for different magneticalignment systems, according to some embodiments.

FIG. 7 shows a simplified top-down view of a secondary alignmentcomponent according to some embodiments.

FIG. 8A shows a perspective view of a magnetic alignment systemaccording to some embodiments, and FIGS. 8B and 8C show axialcross-section views through different portions of the system of FIG. 8A.

FIGS. 9A and 9B show simplified top-down views of secondary alignmentcomponents according to various embodiments.

FIG. 10 shows a simplified top-down view of a secondary alignmentcomponent according to some embodiments.

FIG. 11 illustrates an example of an annular alignment component havinga gap according to some embodiments.

FIGS. 12A and 12B show examples portable electronic devicesincorporating a magnetic alignment component according to someembodiments.

FIG. 13 shows a simplified view of a wireless charger deviceincorporating a magnetic alignment component according to someembodiments.

FIG. 14A shows a simplified perspective view of a system including aportable electronic device in alignment with a wireless charger deviceaccording to some embodiments, and FIG. 14B shows a simplified partialcross section view of the system of FIG. 14A.

FIG. 15 is a block diagram illustrating an exemplary wireless chargingsystem including devices that can be aligned together via a magneticalignment system according to some embodiments.

FIG. 16 shows an example of a portable electronic device and anaccessory incorporating a magnetic alignment system with an annularalignment component and a rotational alignment component according tosome embodiments.

FIGS. 17A and 17B show an example of rotational alignment according tosome embodiments.

FIGS. 18A and 18B show a perspective view and a top view of a rotationalalignment component having a “z-pole” configuration according to someembodiments.

FIGS. 19A and 19B show a perspective view and a top view of a rotationalalignment component having a “quad-pole” configuration according to someembodiments.

FIGS. 20A and 20B show a perspective view and a top view of a rotationalalignment component having an “annulus design” configuration accordingto some embodiments.

FIGS. 21A and 21B show a perspective view and a top view of a rotationalalignment component having a “triple pole” configuration according tosome embodiments.

FIG. 22 shows graphs of torque as a function of angular rotation formagnetic alignment systems having rotational alignment componentsaccording to various embodiments.

FIG. 23 shows a portable electronic device having an alignment systemwith multiple rotational alignment components according to someembodiments.

FIG. 24 shows a simplified representation of a wireless charging systemincorporating a magnetic alignment system according to some embodiments.

FIG. 25A shows a perspective view of a magnetic alignment systemaccording to some embodiments, and FIG. 25B shows a cross-sectionthrough the magnetic alignment system of FIG. 25A.

FIG. 26A shows a perspective view of a magnetic alignment systemaccording to some embodiments, and FIG. 26B shows a cross-sectionthrough the magnetic alignment system of FIG. 26A.

FIG. 27 shows a simplified rear view of an accessory deviceincorporating a magnetic alignment component according to someembodiments.

FIG. 28A shows a simplified perspective view of a system including aportable electronic device in alignment with an accessory device and awireless charger device according to some embodiments, and FIG. 28Bshows a simplified partial cross section view of the system of FIG. 28A.

FIG. 29 is a block diagram illustrating an exemplary wireless chargingsystem including devices that can be aligned together via a magneticalignment system according to some embodiments.

FIGS. 30A-30C illustrate moving magnets according to an embodiment ofthe present invention.

FIGS. 31A and 31B illustrate a moving magnetic structure according to anembodiment of the present invention.

FIGS. 32A and 32B illustrate a moving magnetic structure according to anembodiment of the present invention.

FIGS. 33-35 illustrate a moving magnetic structure according to anembodiment of the present invention.

FIG. 36 illustrates a normal force between a first magnet in a firstelectronic device and a second magnet in a second electronic device.

FIG. 37 illustrates a shear force between a first magnet in a firstelectronic device and a second magnet in a second electronic device.

FIGS. 38A and 38B illustrate a moving magnet in conjunction with a highfriction surface according to an embodiment of the present invention.

FIGS. 39A and 39B illustrate a moving magnet in conjunction with a highfriction surface according to an embodiment of the present invention.

FIGS. 40A and 40B illustrate a moving magnet in conjunction with a highfriction surface according to an embodiment of the present invention.

FIGS. 41A and 41B illustrate another moving magnet in conjunction with ahigh friction surface according to an embodiment of the presentinvention.

FIG. 42 illustrates a cutaway side view of another moving magnetstructure according to an embodiment of the present invention.

FIG. 43 is a partially transparent view of the moving magnet structureof FIG. 42 .

FIG. 44 is another cutaway side view of the electronic device of FIG. 42.

FIGS. 45 and 46 illustrate the electronic device of FIG. 42 as itengages with a second electronic device.

FIGS. 47A and 47B illustrate structures for constraining motions ofmagnets in an electronic device according to an embodiment of thepresent invention.

FIGS. 48A and 48B illustrate structures for constraining motions ofmagnets in an electronic device according to an embodiment of thepresent invention.

FIGS. 49A and 49B illustrate structures for constraining motions ofmagnets an electronic device according to an embodiment of the presentinvention.

DETAILED DESCRIPTION

Described herein are various embodiments of magnetic alignment systemsand components thereof. A magnetic alignment system can include annularalignment components, where each annular alignment component cancomprise a ring of magnets (or a single annular magnet) having aparticular magnetic orientation or pattern of magnetic orientations suchthat a “primary” annular alignment component can attract and hold acomplementary “secondary” annular alignment component. Magneticalignment components can be incorporated into a variety of devices, anda magnetic alignment component in one device can attract another devicehaving a complementary magnetic alignment component into a desiredalignment and/or hold the other device in a desired alignment. (Devicesaligned by a magnetic alignment system may be said to be “attached” toeach other.)

For purposes of the present description, a number of differentcategories of devices can be distinguished. As used herein, a “portableelectronic device” refers generally to any electronic device that isportable and that consumes power and provides at least some interactionwith the user. Examples of portable electronic devices include: smartphones and other mobile phones; tablet computers; laptop computers;wearable devices (e.g., smart watches, headphones, earbuds); and anyother electronic device that a user may carry or wear. Other portableelectronic devices can include robotic devices, remote-controlleddevices, personal-care appliances, and so on.

An “accessory device” (or “accessory”) refers generally to a device thatis useful in connection with a portable electronic device to enhance thefunctionality and/or esthetics of the portable electronic device. Manycategories of accessories may incorporate magnetic alignment. Forexample, one category of accessories includes wireless chargeraccessories. As used herein, a “wireless charger accessory” (or“wireless charger device” or just “wireless charger”) is an accessorythat can provide power to a portable electronic device using wirelesspower transfer techniques. A “battery pack” (or “external battery”) is atype of wireless charger accessory that incorporates a battery to storecharge that can be transferred to the portable electronic device. Insome embodiments, a battery pack may also receive power wirelessly fromanother wireless charger accessory. Wireless charger accessories mayalso be referred to as “active” accessories, in reference to theirability to provide and/or receive power. Other accessories are “passiveaccessories” that do not provide or receive power. For example, somepassive accessories are “cases” that can cover one or more surfaces ofthe portable electronic device to provide protection (e.g., againstdamage caused by impact of the portable electronic device with otherobjects), esthetic enhancements (e.g., decorative colors or the like),and/or functional enhancements (e.g., cases that incorporate storagepockets, batteries, card readers, or sensors of various types). Casescan have a variety of form factors. For example, a “tray” can refer to acase that has a rear panel covering the back surface of the portableelectronic device and side surfaces to secure the portable electronicdevice in the tray while leaving the front surface (which may include adisplay) exposed. A “sleeve” can refer to a case that has front and backpanels with an open end (or “throat”) into which a portable electronicdevice can be inserted so that the front and back surfaces of the deviceare covered; in some instances, the front panel of a sleeve can includea window through which a portion (or all) of a display of the portableelectronic device is visible. A “folio” can refer to a case that has aretention portion that covers at least the back surface (and sometimesalso one or more side surfaces) of the portable electronic device and acover that can be closed to cover the display or opened to expose thedisplay. It should be understood that not all cases are passiveaccessories. For example, a “battery case” can incorporate a batterypack in addition to protective and/or esthetic features; a battery casecan be shaped generally as a tray, sleeve, or folio. Other examples ofactive cases can include cases that incorporate card readers, sensors,batteries, or other electronic components that enhance functionality ofa portable electronic device.

In the present description, a distinction is sometimes made between a“charge-through accessory,” which is an accessory that can be positionedbetween a portable electronic device and a wireless charger devicewithout interfering with wireless power transfer between the wirelesscharger device and the portable electronic device, and a “terminalaccessory,” which is an accessory that is not a charge-throughaccessory. A wireless charging accessory is typically a terminalaccessory, but not all terminal accessories provide wireless charging ofa portable electronic device. For example some terminal accessories canbe “mounting” accessories that are designed to hold the portableelectronic device in a particular position. Examples of mounting includetripods, docking stations, other stands, or mounts that can hold aportable electronic device in a desired position and/or orientation(which might or might not be adjustable). Such accessories might ormight not incorporate wireless charging capability.

According to embodiments described herein, a portable electronic deviceand an accessory device can include complementary magnetic alignmentcomponents that facilitate alignment of the accessory device with theportable electronic device and/or attachment of the accessory device tothe portable electronic device. The magnetic alignment components caninclude annular magnetic alignment components that, in some embodiments,can surround inductive charging transmitter and receiver coils. (It willbe apparent that an annular magnetic alignment component can also beused in a device that does not have an inductive charging coil.) In thenomenclature used herein, a “primary” annular magnetic alignmentcomponent refers to an annular magnetic alignment component used in awireless charger device or other terminal accessory. A “secondary”annular magnetic alignment component refers to an annular magneticalignment component used in a portable electronic device. An “auxiliary”annular magnetic alignment component refers to an annular magneticalignment component used in a charge-through accessory. (In thisdisclosure, adjectives such as “annular,” “magnetic,” “primary,”“secondary” and “auxiliary” may be omitted when the context is clear.)The primary and secondary annular alignment components have magneticorientations that are complementary, such that the primary and secondaryannular alignment components can attract each other and attach devicescontaining these components in a desired alignment. For example, aprimary annular alignment component can have a “quad-pole” magneticconfiguration, with an inner annular region having a magnetic polarityin a first axial direction, an outer annular region having a magneticpolarity in a second axial direction opposite the first direction, and acentral non-magnetized region between the inner annular region and theouter annular region. A secondary annular alignment component can have aradial magnetic configuration (e.g., with north pole oriented radiallyinward or radially outward, either exactly or approximately; examplesare described below). When aligned, the primary and secondary annularalignment components can form a closed magnetic loop such that the DCmagnetic flux is largely contained within the magnets. Alternatively, asecondary annular alignment component can also have a quad-pole magneticconfiguration matching that of the primary annular alignment component.An auxiliary annular alignment component can operate as a “repeater” andcan have a quad-pole configuration matching that of the primary annularalignment component.

In some embodiments, a magnetic alignment system can also include arotational magnetic alignment component that facilitates aligning twodevices in a preferred rotational orientation. A rotational magneticalignment component can include, for example, one or more magnetsdisposed outboard of an annular alignment component. The magnet(s) of arotational alignment component can have complementary orientations, suchthe rotational alignment components in two devices can attract eachother and attach the two devices containing these components in adesired rotational orientation. For example, a rotational alignmentcomponent can have a quad-pole configuration with a first magnetizedregion (e.g., extending along one side of a rectangular magnet) having amagnetic polarity in a first axial direction, a second magnetized region(e.g., extending along the opposite side of the rectangular magnet)having a magnetic polarity in a second axial direction opposite thefirst direction, and a central non-magnetized region. As anotherexample, a rotational alignment component can have a triple-poleconfiguration with a first magnetized region (e.g., extending along oneside of a rectangular magnet) having a magnetic polarity in a firstaxial direction, a second magnetized region (e.g., extending along theopposite side of the rectangular magnet) also having a magnetic polaritythe first axial direction, a central magnetized region having a magneticpolarity in a second axial direction opposite the first direction, andnon-magnetized regions between the central magnetized region and each ofthe first and second magnetized regions. Other magnetic configurationscan be substituted. It should be understood that any device that has anannular magnetic alignment component might or might not also have arotational magnetic alignment component, and rotational alignmentcomponents may be categorized as primary, secondary, or auxiliary, e.g.,depending on the type of device.

In some embodiments, magnetic alignment components can be fixed inposition within a device housing. Alternatively, any or all of themagnetic alignment components in a device (including annular and/orrotational alignment components) can be made movable in the axial and/orlateral direction. A movable magnetic alignment component can allow themagnets to be moved (e.g., axially) into closer proximity to increasemagnetic forces holding the devices in alignment or moved away from eachother to reduce the magnetic forces holding the devices in alignment.

Accordingly, while the following description focuses on specificexamples incorporating various combinations of components, it should beunderstood that any device can have has an annular magnetic alignmentcomponent, which can be, for example, any of the primary, secondary, orauxiliary annular magnetic alignment components described herein.Further, any device that has an annular magnetic alignment component canalso have a rotational magnetic alignment component, which can be, forexample, any of the rotational magnetic alignment components describedherein.

1. Primary and Secondary Annular Magnetic Alignment Components

1.1. Overview of Magnetic Alignment Systems

FIG. 1 shows a simplified representation of a wireless charging system100 incorporating a magnetic alignment system 106 according to someembodiments. A portable electronic device 104 is positioned on acharging surface 108 of a wireless charger device 102. Portableelectronic device 104 can be a consumer electronic device, such as asmart phone, tablet, wearable device, or the like, or any otherelectronic device for which wireless charging is desired. Wirelesscharger device 102 can be any device that is configured to generatetime-varying magnetic flux to induce a current in a suitably configuredreceiving device. For instance, wireless charger device 102 can be awireless charging mat, puck, docking station, or the like. Wirelesscharger device 102 can include or have access to a power source such asbattery power or standard AC power.

To enable wireless power transfer, portable electronic device 104 andwireless charger device 102 can include inductive coils 110 and 112,respectively, which can operate to transfer power between them. Forexample, inductive coil 112 can be a transmitter coil that generates atime-varying magnetic flux 114, and inductive coil 110 can be a receivercoil in which an electric current is induced in response to time-varyingmagnetic flux 114. The received electric current can be used to charge abattery of portable electronic device 104, to provide operating power toa component of portable electronic device 104, and/or for other purposesas desired. (“Wireless power transfer” and “inductive power transfer,”as used herein, refer generally to the process of generating atime-varying magnetic field in a conductive coil of a first device thatinduces an electric current in a conductive coil of a second device.)

To enable efficient wireless power transfer, it is desirable to aligninductive coils 112 and 110. According to some embodiments, magneticalignment system 106 can provide such alignment. In the example shown inFIG. 1 , magnetic alignment system 106 includes a primary magneticalignment component 116 disposed within or on a surface of wirelesscharger device 102 and a secondary magnetic alignment component 118disposed within or on a surface of portable electronic device 102.Primary and secondary alignment components 116 and 118 are configured tomagnetically attract one another into an aligned position in whichinductive coils 110 and 112 are aligned with one another to provideefficient wireless power transfer.

According to embodiments described herein, a magnetic alignmentcomponent (including a primary or secondary alignment component) of amagnetic alignment system can be formed of arcuate magnets arranged inan annular configuration. In some embodiments, each magnet can have itsmagnetic polarity oriented in a desired direction so that magneticattraction between the primary and secondary magnetic alignmentcomponents provides a desired alignment. In some embodiments, an arcuatemagnet can include a first magnetic region with magnetic polarityoriented in a first direction and a second magnetic region with magneticpolarity oriented in a second direction different from (e.g., oppositeto) the first direction. As will be described, different configurationscan provide different degrees of magnetic field leakage.

1.2. Magnetic Alignment Systems with a Single Axial Magnetic Orientation

FIG. 2A shows a perspective view of a magnetic alignment system 200according to some embodiments, and FIG. 2B shows a cross-section throughmagnetic alignment system 200 across the cut plane indicated in FIG. 2A.Magnetic alignment system 200 can be an implementation of magneticalignment system 106 of FIG. 1 . In magnetic alignment system 200, thealignment components all have magnetic polarity oriented in the samedirection (along the axis of the annular configuration). For convenienceof description, an “axial” direction (also referred to as a“longitudinal” or “z” direction) is defined to be parallel to an axis ofrotational symmetry 201 of magnetic alignment system 200, and atransverse plane (also referred to as a “lateral” or “x” or “y”direction) is defined to be normal to axis 201. The term “proximal side”or “proximal surface” is used herein to refer to a side or surface ofone alignment component that is oriented toward the other alignmentcomponent when the magnetic alignment system is aligned, and the term“distal side” or “distal surface” is used to refer to a side or surfaceopposite the proximal side or surface. (The terms “top” and “bottom” maybe used in reference to a particular view shown in a drawing but have noother significance.)

As shown in FIG. 2A, magnetic alignment system 200 can include a primaryalignment component 216 (which can be an implementation of primaryalignment component 116 of FIG. 1 ) and a secondary alignment component218 (which can be an implementation of secondary alignment component 118of FIG. 1 ). Primary alignment component 216 and secondary alignmentcomponent 218 have annular shapes and may also be referred to as“annular” alignment components. The particular dimensions can be chosenas desired. In some embodiments, primary alignment component 216 andsecondary alignment component 218 can each have an outer diameter ofabout 54 mm and a radial width of about 4 mm. The outer diameters andradial widths of primary alignment component 216 and secondary alignmentcomponent 218 need not be exactly equal. For instance, the radial widthof secondary alignment component 218 can be slightly less than theradial width of primary alignment component 216 and/or the outerdiameter of secondary alignment component 218 can also be slightly lessthan the radial width of primary alignment component 216 so that, whenin alignment, the inner and outer sides of primary alignment component216 extend beyond the corresponding inner and outer sides of secondaryalignment component 218. Thicknesses (or axial dimensions) of primaryalignment component 216 and secondary alignment component 218 can alsobe chosen as desired. In some embodiments, primary alignment component216 has a thickness of about 1.5 mm while secondary alignment component218 has a thickness of about 0.37 mm.

Primary alignment component 216 can include a number of sectors, each ofwhich can be formed of one or more primary arcuate magnets 226, andsecondary alignment component 218 can include a number of sectors, eachof which can be formed of one or more secondary arcuate magnets 228. Inthe example shown, the number of primary magnets 226 is equal to thenumber of secondary magnets 228, and each sector includes exactly onemagnet, but this is not required. Primary magnets 226 and secondarymagnets 228 can have arcuate (or curved) shapes in the transverse planesuch that when primary magnets 226 (or secondary magnets 228) arepositioned adjacent to one another end-to-end, primary magnets 226 (orsecondary magnets 228) form an annular structure as shown. In someembodiments, primary magnets 226 can be in contact with each other atinterfaces 230, and secondary magnets 228 can be in contact with eachother at interfaces 232. Alternatively, small gaps or spaces mayseparate adjacent primary magnets 226 or secondary magnets 228,providing a greater degree of tolerance during manufacturing.

In some embodiments, primary alignment component 216 can also include anannular shield 214 (also referred to as a DC magnetic shield or DCshield) disposed on a distal surface of primary magnets 226. In someembodiments, shield 214 can be formed as a single annular piece ofmaterial and adhered to primary magnets 226 to secure primary magnets226 into position. Shield 214 can be formed of a material that has highmagnetic permeability, such as stainless steel, and can redirectmagnetic fields to prevent them from propagating beyond the distal sideof primary alignment component 216, thereby protecting sensitiveelectronic components located beyond the distal side of primaryalignment component 216 from magnetic interference.

Primary magnets 226 and secondary magnets 228 (and all other magnetsdescribed herein) can be made of a magnetic material such as an NdFeBmaterial, other rare earth magnetic materials, or other materials thatcan be magnetized to create a persistent magnetic field. In someembodiments, the magnets can be plated with a thin layer (e.g., 7-13 μm)of NiCuNi or similar materials. Each primary magnet 226 and eachsecondary magnet 228 can have a monolithic structure having a singlemagnetic region with a magnetic polarity aligned in the axial directionas shown by magnetic polarity indicators 215, 217 in FIG. 2B. Forexample, each primary magnet 226 and each secondary magnet 228 can be abar magnet that has been ground and shaped into an arcuate structurehaving an axial magnetic orientation. (As will be apparent, the term“magnetic orientation” refers to the direction of orientation of themagnetic polarity of a magnet or magnetized region.) In the exampleshown, primary magnet 226 has its north pole oriented toward theproximal surface and south pole oriented toward the distal surface whilesecondary magnet 228 has its south pole oriented toward the proximalsurface and north pole oriented toward the distal surface. In otherembodiments, the magnetic orientations can be reversed such that primarymagnet 226 has its south pole oriented toward the proximal surface andnorth pole oriented toward the distal surface while secondary magnet 228has its north pole oriented toward the proximal surface and south poleoriented toward the distal surface.

As shown in FIG. 2B, the axial magnetic orientation of primary magnet226 and secondary magnet 228 can generate magnetic fields 240 that exertan attractive force between primary magnet 226 and secondary magnet 228,thereby facilitating alignment between respective electronic devices inwhich primary alignment component 216 and secondary alignment component218 are disposed (e.g., as shown in FIG. 1 ). While shield 214 canredirect some of magnetic fields 240 away from regions below primarymagnet 226, magnetic fields 240 may still propagate to regions laterallyadjacent to primary magnet 226 and secondary magnet 228. In someembodiments, the lateral propagation of magnetic fields 240 may resultin magnetic field leakage to other magnetically sensitive components.For instance, if an inductive coil having a ferromagnetic shield isplaced in the interior (or inboard) region of annular primary alignmentcomponent 216 (or secondary alignment component 218), leakage ofmagnetic fields 240 may saturate the ferrimagnetic shield, which candegrade wireless charging performance.

It will be appreciated that magnetic alignment system 200 isillustrative and that variations and modifications are possible. Forinstance, while primary alignment component 216 and secondary alignmentcomponent 218 are each shown as being constructed of eight arcuatemagnets, other embodiments may use a different number of magnets, suchas sixteen magnets, thirty-six magnets, or any other number of magnets,and the number of primary magnets need not be equal to the number ofsecondary magnets. In other embodiments, primary alignment component 216and/or secondary alignment component 218 can each be formed of a single,monolithic annular magnet; however, segmenting magnetic alignmentcomponents 216 and 218 into arcuate magnets may improve manufacturingbecause (for some types of magnetic material) smaller arcuate segmentsmay be less brittle than a single, monolithic annular magnet and lessprone to yield loss due to physical stresses imposed on the magneticmaterial during manufacturing.

1.3. Magnetic Alignment Systems with Closed-Loop Configurations

As noted above with reference to FIG. 2B, a magnetic alignment systemwith a single axial magnetic orientation may allow lateral leakage ofmagnetic fields, which may adversely affect performance of othercomponents of an electronic device. Accordingly, some embodimentsprovide magnetic alignment systems with a “closed-loop” configurationthat reduces magnetic field leakage. Examples will now be described.

FIG. 3A shows a perspective view of a magnetic alignment system 300according to some embodiments, and FIG. 3B shows a cross-section throughmagnetic alignment system 300 across the cut plane indicated in FIG. 3A.Magnetic alignment system 300 can be an implementation of magneticalignment system 106 of FIG. 1 . In magnetic alignment system 300, thealignment components have magnetic components configured in a “closedloop” configuration as described below.

As shown in FIG. 3A, magnetic alignment system 300 can include a primaryalignment component 316 (which can be an implementation of primaryalignment component 116 of FIG. 1 ) and a secondary alignment component318 (which can be an implementation of secondary alignment component 118of FIG. 1 ). Primary alignment component 316 and secondary alignmentcomponent 318 have annular shapes and may also be referred to as“annular” alignment components. The particular dimensions can be chosenas desired. In some embodiments, primary alignment component 316 andsecondary alignment component 318 can each have an outer diameter ofabout 54 mm and a radial width of about 4 mm. The outer diameters andradial widths of primary alignment component 316 and secondary alignmentcomponent 318 need not be exactly equal. For instance, the radial widthof secondary alignment component 318 can be slightly less than theradial width of primary alignment component 316 and/or the outerdiameter of secondary alignment component 318 can also be slightly lessthan the radial width of primary alignment component 316 so that, whenin alignment, the inner and outer sides of primary alignment component316 extend beyond the corresponding inner and outer sides of secondaryalignment component 318. Thicknesses (or axial dimensions) of primaryalignment component 316 and secondary alignment component 318 can alsobe chosen as desired. In some embodiments, primary alignment component316 has a thickness of about 1.5 mm while secondary alignment component318 has a thickness of about 0.37 mm. (All numerical values herein areexamples and may be varied as desired.)

Primary alignment component 316 can include a number of sectors, each ofwhich can be formed of a number of primary magnets 326, and secondaryalignment component 318 can include a number of sectors, each of whichcan be formed of a number of secondary magnets 328. In the exampleshown, the number of primary magnets 326 is equal to the number ofsecondary magnets 328, and each sector includes exactly one magnet, butthis is not required; for example, as described below a sector mayinclude multiple magnets. Primary magnets 326 and secondary magnets 328can have arcuate (or curved) shapes in the transverse plane such thatwhen primary magnets 326 (or secondary magnets 328) are positionedadjacent to one another end-to-end, primary magnets 326 (or secondarymagnets 328) form an annular structure as shown. In some embodiments,primary magnets 326 can be in contact with each other at interfaces 330,and secondary magnets 328 can be in contact with each other atinterfaces 332. Alternatively, small gaps or spaces may separateadjacent primary magnets 326 or secondary magnets 328, providing agreater degree of tolerance during manufacturing.

In some embodiments, primary alignment component 316 can also include anannular shield 314 (also referred to as a DC magnetic shield or DCshield) disposed on a distal surface of primary magnets 326. In someembodiments, shield 314 can be formed as a single annular piece ofmaterial and adhered to primary magnets 326 to secure primary magnets326 into position. Shield 314 can be formed of a material that has highmagnetic permeability and/or high magnetic saturation value, such asstainless steel or low-carbon steel, and can redirect magnetic fields toprevent them from propagating beyond the distal side of primaryalignment component 316, thereby protecting sensitive electroniccomponents located beyond the distal side of primary alignment component316 from magnetic interference.

Primary magnets 326 and secondary magnets 328 can be made of a magneticmaterial such as an NdFeB material, other rare earth magnetic materials,or other materials that can be magnetized to create a persistentmagnetic field. Each secondary magnet 328 can have a single magneticregion with a magnetic polarity having a component in the radialdirection in the transverse plane (as shown by magnetic polarityindicator 317 in FIG. 3B). As described below, the magnetic orientationcan be in a radial direction with respect to axis 301 or anotherdirection having a radial component in the transverse plane. Eachprimary magnet 326 can include two magnetic regions having oppositemagnetic orientations. For example, each primary magnet 326 can includean inner arcuate magnetic region 352 having a magnetic orientation in afirst axial direction (as shown by polarity indicator 353 in FIG. 3B),an outer arcuate magnetic region 354 having a magnetic orientation in asecond axial direction opposite the first direction (as shown bypolarity indicator 355 in FIG. 3B), and a central non-magnetized region356 that does not have a magnetic orientation. Central non-magnetizedregion 356 can magnetically separate inner arcuate region 352 from outerarcuate region 354 by inhibiting magnetic fields from directly crossingthrough central region 356. Magnets having regions of opposite magneticorientation separated by a non-magnetized region are sometimes referredto herein as having a “quad-pole” configuration.

In some embodiments, each secondary magnet 328 can be made of a magneticmaterial that has been ground and shaped into an arcuate structure, anda magnetic orientation having a radial component in the transverse planecan be created, e.g., using a magnetizer. Similarly, each primary magnet326 can be made of a single piece of magnetic material that has beenground and shaped into an arcuate structure, and a magnetizer can beapplied to the arcuate structure to induce an axial magnetic orientationin one direction within an inner arcuate region of the structure and anaxial magnetic orientation in the opposite direction within an outerarcuate region of the structure, while demagnetizing or avoidingcreation of a magnetic orientation in the central region. In somealternative embodiments, each primary magnet 326 can be a compoundstructure with two arcuate pieces of magnetic material providing innerarcuate magnetic region 352 and outer arcuate magnetic region 354; insuch embodiments, central non-magnetized region 356 can be formed of anarcuate piece of nonmagnetic (or demagnetized) material or formed as anair gap defined by sidewalls of inner arcuate magnetic region 352 andouter arcuate magnetic region 354. DC shield 314 can be formed of amaterial that has high magnetic permeability and/or high magneticsaturation value, such as stainless steel or low-carbon steel, and canbe plated, e.g., with 5-10 μm of matte Ni. Alternatively, DC shield 314can be formed of a magnetic material having a radial magneticorientation (in the opposite direction of secondary magnets 328). Insome embodiments, DC shield 314 can be omitted entirely.

As shown in FIG. 3B, the magnetic polarity of secondary magnet 328(shown by indicator 317) can be oriented such that when primaryalignment component 316 and secondary alignment component 318 arealigned, the south pole of secondary magnet 328 is oriented toward thenorth pole of inner arcuate magnetic region 352 (shown by indicator 353)while the north pole of secondary magnet 328 is oriented toward thesouth pole of outer arcuate magnetic region 354 (shown by indicator355). Accordingly, the respective magnetic orientations of inner arcuatemagnetic region 352, secondary magnet 328 and outer arcuate magneticregion 356 can generate magnetic fields 340 that exert an attractiveforce between primary magnet 326 and secondary magnet 328, therebyfacilitating alignment between respective electronic devices in whichprimary alignment component 316 and secondary alignment component 318are disposed (e.g., as shown in FIG. 1 ). Shield 314 can redirect someof magnetic fields 340 away from regions below primary magnet 326.Further, the “closed-loop” magnetic field 340 formed around centralnon-magnetized region 356 can have tight and compact field lines that donot stray outside of primary and secondary magnets 326 and 328 as far asmagnetic field 240 strays outside of primary and secondary magnets 226and 228 in FIG. 2B. Thus, magnetically sensitive components can beplaced relatively close to primary alignment component 316 with reducedconcern for stray magnetic fields. Accordingly, as compared to magneticalignment system 200, magnetic alignment system 300 can help to reducethe overall size of a device in which primary alignment component 316 ispositioned and can also help reduce noise created by magnetic field 340in adjacent components or devices, such as an inductive receiver coilpositioned inboard of secondary alignment component 318.

While each primary magnet 326 includes two regions of opposite magneticorientation, it should be understood that the two regions can but neednot provide equal magnetic field strength. For example, outer arcuatemagnetized region 354 can be more strongly polarized than inner arcuatemagnetized region 352. Depending on the particular implementation ofprimary magnets 326, various techniques can be used to create asymmetricpolarization strength. For example, inner arcuate region 352 and outerarcuate region 354 can have different radial widths; increasing radialwidth of a magnetic region increases the field strength of that regiondue to increased volume of magnetic material. Where inner arcuate region352 and outer arcuate region 354 are discrete magnets, magnets havingdifferent magnetic strength can be used.

In some embodiments, having an asymmetric polarization where outerarcuate region 354 is more strongly polarized than inner arcuate region352 can create a flux “sinking” effect toward the outer pole. Thiseffect can be desirable in various situations. For example, when primarymagnet 326 is disposed within a wireless charger device and the wirelesscharger device is used to charge a “legacy” portable electronic devicethat has an inductive receiver coil but does not have a secondary (orany) annular magnetic alignment component, the (DC) magnetic flux fromthe primary annular alignment component may enter a ferrite shieldaround the inductive receiver coil. The DC magnetic flux can contributeto saturating the ferrite shield and reducing charging performance.Providing a primary annular alignment component with a stronger field atthe outer arcuate region than the inner arcuate region can help to drawDC magnetic flux away from the ferrite shield, which can improvecharging performance when a wireless charger device having an annularmagnetic alignment component is used to charge a portable electronicdevice that lacks an annular magnetic alignment component.

It will be appreciated that magnetic alignment system 300 isillustrative and that variations and modifications are possible. Forinstance, while primary alignment component 316 and secondary alignmentcomponent 318 are each shown as being constructed of eight arcuatemagnets, other embodiments may use a different number of magnets, suchas 16 magnets, 18 magnets, 32 magnets, 36 magnets, or any other numberof magnets, and the number of primary magnets need not be equal to thenumber of secondary magnets. In other embodiments, secondary alignmentcomponent 318 can be formed of a single, monolithic annular magnet.Similarly, primary alignment component 316 can be formed of a single,monolithic annular piece of magnetic material with an appropriatemagnetization pattern as described above, or primary alignment component316 can be formed of a monolithic inner annular magnet and a monolithicouter annular magnet, with an annular air gap or region of nonmagneticmaterial disposed between the inner annular magnet and outer annularmagnet.

In some embodiments, a construction using multiple arcuate magnets mayimprove manufacturing because smaller arcuate magnets are less brittlethan a single, monolithic annular magnet and are less prone to yieldloss due to physical stresses imposed on the magnetic material duringmanufacturing. It should also be understood that the magneticorientations of the various magnetic alignment components or individualmagnets do not need to align exactly with the lateral and axialdirections. The magnetic orientation can have any angle that provides aclosed-loop path for a magnetic field through the primary and secondaryalignment components.

1.4. Magnetic Orientation for a Closed-Loop Magnetic Alignment System

1.4.1. Radially Symmetric Orientation

As noted above, in embodiments of magnetic alignment systems havingclosed-loop magnetic orientations, such as magnetic alignment system300, secondary alignment component 318 can have a magnetic orientationwith a radial component. For example, in some embodiments, secondaryalignment component 318 can have a magnetic polarity in a radialorientation. FIG. 4 shows a simplified top-down view of a secondaryalignment component 418 according to some embodiments. Secondaryalignment component 418, like secondary alignment component 318, can beformed of arcuate magnets 428 a-h having radial magnetic orientations asshown by magnetic polarity indicators 417 a-h. In this example, eacharcuate magnet 428 a-h has a north magnetic pole oriented toward theradially outward side and a south magnetic pole toward the radiallyinward side; however, this orientation can be reversed, and the northmagnetic pole of each arcuate magnet 428 a-h can be oriented toward theradially inward side while the south magnetic pole is oriented towardthe radially outward side.

FIG. 5A shows a perspective view of a magnetic alignment system 500according to some embodiments. Magnetic alignment system 500, which canbe an implementation of magnetic alignment system 300, includes asecondary alignment component 518 having a radially outward magneticorientation (e.g., as shown in FIG. 4 ) and a complementary primaryalignment component 516. In this example, magnetic alignment system 500includes a gap 507 between two of the sectors; however, gap 507 isoptional and magnetic alignment system 500 can be a complete annularstructure. Also shown are components 502, which can include, for examplean inductive coil assembly or other components located within thecentral region of primary magnetic alignment component 516 or secondarymagnetic alignment component 518. Magnetic alignment system 500 can havea closed-loop configuration similar to magnetic alignment system 300 (asshown in FIG. 3B) and can include arcuate sectors 501, each of which canbe made of one or more arcuate magnets. In some embodiments, theclosed-loop configuration of magnetic alignment system 500 can reduce orprevent magnetic field leakage that may affect components 502.

FIG. 5B shows an axial cross-section view through one of arcuate sectors501. Arcuate sector 501 includes a primary magnet 526 and a secondarymagnet 528. As shown by orientation indicator 517, secondary magnet 528has a magnetic polarity oriented in a radially outward direction, i.e.,the north magnetic pole is toward the radially outward side of magneticalignment system 500. Like primary magnets 326 described above, primarymagnet 526 includes an inner arcuate magnetic region 552, an outerarcuate magnetic region 554, and a central non-magnetized region 556(which can include, e.g., an air gap or a region of nonmagnetic ornon-magnetized material). Inner arcuate magnetic region 552 has amagnetic polarity oriented axially such that the north magnetic pole istoward secondary magnet 528, as shown by indicator 553, while outerarcuate magnetic region 554 has an opposite magnetic orientation, withthe south magnetic pole oriented toward secondary magnet 528, as shownby indicator 555. As described above with reference to FIG. 3B, thearrangement of magnetic orientations shown in FIG. 5B results inmagnetic attraction between primary magnet 526 and secondary magnet 528.In some embodiments, the magnetic polarities can be reversed such thatthe north magnetic pole of secondary magnet 528 is oriented toward theradially inward side of magnetic alignment system 500, the northmagnetic pole of outer arcuate region 554 of primary magnet 526 isoriented toward secondary magnet 528, and the north magnetic pole ofinner arcuate region 552 is oriented away from secondary magnet 528.

When primary alignment component 516 and secondary alignment component518 are aligned, the radially symmetrical arrangement and directionalequivalence of magnetic polarities of primary alignment component 516and secondary alignment component 518 allow secondary alignmentcomponent 518 to rotate freely (relative to primary alignment component516) in the clockwise or counterclockwise direction in the lateral planewhile maintaining alignment along the axis.

As used herein, a “radial” orientation need not be exactly or purelyradial. For example, FIG. 5C shows a secondary arcuate magnet 538according to some embodiments. Secondary arcuate magnet 538 has a purelyradial magnetic orientation, as indicated by arrows 539. Each arrow 539is directed at the center of curvature of magnet 538; if extendedinward, arrows 539 would converge at the center of curvature. However,achieving this purely radial magnetization requires that magneticdomains within magnet 538 be oriented obliquely to neighboring magneticdomains. For some types of magnetic materials, purely radial magneticorientation may not be practical. Accordingly, some embodiments use a“pseudo-radial” magnetic orientation that approximates the purely radialorientation of FIG. 5C. FIG. 5D shows a secondary arcuate magnet 548with pseudo-radial magnetic orientation according to some embodiments.Magnet 548 has a magnetic orientation, shown by arrows 549, that isperpendicular to a baseline 551 connecting the inner corners 552, 553 ofarcuate magnet 548. If extended inward, arrows 549 would not converge.Thus, neighboring magnetic domains in magnet 548 are parallel to eachother, which is readily achievable in magnetic materials such as NdFeB.The overall effect in a magnetic alignment system, however, can besimilar to the purely radial magnetic orientation shown FIG. 5C. FIG. 5Eshows a secondary annular alignment component 558 made up of magnets 548according to some embodiments. Magnetic orientation arrows 549 have beenextended to the center point 561 of annular alignment component 558. Asshown the magnetic field direction can be approximately radial, with thecloseness of the approximation depending on the number of magnets 548and the inner radius of annular alignment component 558. In someembodiments, 18 magnets 548 can provide a pseudo-radial orientation; inother embodiments, more or fewer magnets can be used. It should beunderstood that all references herein to magnets having a “radial”magnetic orientation include pseudo-radial magnetic orientations andother magnetic orientations that are approximately but not purelyradial.

In some embodiments, a radial magnetic orientation in a secondaryalignment component 518 (e.g., as shown in FIG. 5B) provides a magneticforce profile between secondary alignment component 518 and primaryalignment component 516 that is the same around the entire circumferenceof the magnetic alignment system. The radial magnetic orientation canalso result in greater magnetic permeance, which allows secondaryalignment component 518 to resist demagnetization as well as enhancingthe attractive force in the axial direction and improving shear force inthe lateral directions when the two components are aligned.

FIGS. 6A and 6B show graphs of force profiles for different magneticalignment systems, according to some embodiments. Specifically, FIG. 6Ashows a graph 600 of vertical attractive (normal) force in the axial (z)direction for different magnetic alignment systems of comparable sizeand using similar types of magnets. Graph 600 has a horizontal axisrepresenting displacement from a center of alignment, where 0 representsthe aligned position and negative and positive values representdisplacements from the aligned position in opposite directions (inarbitrary units), and a vertical axis showing the normal force(F_(NORMAL)) as a function of displacement in the lateral plane (also inarbitrary units). For purposes of this description, F_(NORMAL) isdefined as the magnetic force between the primary and secondaryalignment components in the axial direction; F_(NORMAL)>0 representsattractive force while F_(NORMAL)<0 represents repulsive force. Graph600 shows normal force profiles for three different types of magneticalignment systems. A first type of magnetic alignment system uses“central” alignment components, such as a pair of complementarydisc-shaped magnets placed along an axis; a representative normal forceprofile for a central magnetic alignment system is shown as line 601(dot-dash line). A second type of magnetic alignment system uses annularalignment components with axial magnetic orientations, e.g., magneticalignment system 200 of FIGS. 2A and 2B; a representative normal forceprofile for such an annular-axial magnetic alignment system is shown asline 603 (dashed line). A third type of magnetic alignment system usesannular alignment components with closed-loop magnetic orientations andradial symmetry (e.g., magnetic alignment system 500 of FIGS. 5A and5B); a representative normal force profile for a radially symmetricclosed-loop magnetic alignment system is shown as line 605 (solid line).

Similarly, FIG. 6B shows a graph 620 of lateral (shear) force in atransverse direction for different magnetic alignment systems. Graph 620has a horizontal axis representing lateral displacement in opposingdirections from a center of alignment, using the same convention asgraph 600, and a vertical axis showing the shear force (F_(SHEAR)) as afunction of direction (in arbitrary units). For purposes of thisdescription, F_(SHEAR) is defined as the magnetic force between theprimary and secondary alignment components in the lateral direction;F_(SHEAR)>0 represents force toward the left along the displacement axiswhile F_(SHEAR)<0 represents force toward the right along thedisplacement axis. Graph 620 shows shear force profiles for the samethree types of magnetic alignment systems as graph 600: a representativeshear force profile for a central magnetic alignment system is shown asline 621 (dot-dash line); a representative shear force profile for anannular-axial magnetic alignment system is shown as line 623 (dashedline); and a representative normal force profile for a radiallysymmetric closed-loop magnetic alignment system is shown as line 625(solid line).

As shown in FIG. 6A, each type of magnetic alignment system achieves thestrongest magnetic attraction in the axial direction (i.e., normalforce) when the primary and secondary alignment components are in thealigned position (0 on the horizontal axis), as shown by respectivepeaks 611, 613, and 615. While the most strongly attractive normal forceis achieved in the aligned positioned for all systems, the magnitude ofthe peak depends on the type of magnetic alignment system. Inparticular, a radially-symmetric closed-loop magnetic alignment system(e.g., magnetic alignment system 500 of FIG. 5 ) provides strongermagnetic attraction when in the aligned position than the other types ofmagnetic alignment systems. This strong attractive normal force canovercome small misalignments and can help to hold devices in the alignedposition, thereby can achieving a more accurate and robust alignmentbetween the primary and secondary alignment components, which in turncan provide a more accurate and robust alignment between a portableelectronic device and a wireless charger device within which themagnetic alignment system is implemented.

As shown in FIG. 6B, the strongest shear forces are obtained when theprimary and secondary alignment components are laterally just outside ofthe aligned position, e.g., at −2 and +2 units of separation from thealigned position, as shown by respective peaks 631 a-b, 633 a-b, and 635a-b. These shear forces act to urge the alignment components toward thealigned position. Similarly to the normal force, the peak strength ofshear force depends on the type of magnetic alignment system. Inparticular, a radially-symmetric closed-loop magnetic alignment system(e.g., magnetic alignment system 500 of FIG. 5 ) provides highermagnitude of shear force when just outside of the aligned position thanthe other types of magnetic alignment systems. This strong shear forcecan provide tactile feedback (sometimes described as a sensation of“snappiness”) to help the user identify when the two components arealigned. In addition, like the normal force, the shear force canovercome small misalignments due to frictional force and can achieve amore accurate and robust alignment between the primary and secondaryalignment components, which in turn can provide a more accurate androbust alignment between a portable electronic device and a wirelesscharger device within which the magnetic alignment system isimplemented.

Depending on the particular configuration of magnets, various designchoices can be used to increase the sensation of snappiness for aclosed-loop magnetic alignment system. For example, reducing the amountof magnetic material in the devices in areas near the magnetic alignmentcomponents—e.g., by using less material or by increasing the distancebetween the magnetic alignment component and the other magneticmaterial—can reduce stray fields and increase the perceived “snapping”effect of the magnetic alignment components. As another example,increasing the magnetic-field strength of the alignment magnets (e.g.,by increasing the amount of material) can increase both shear and normalforces. As yet another example, the widths of the magnetized regions inthe primary annular alignment component (and/or the relative strength ofthe magnetic field in each region) can be optimized based on theparticular magnetic orientation pattern for the secondary annularalignment component (e.g., whether the secondary annular alignmentcomponents have the purely radial magnetic orientation of FIG. 5C or thepseudo-radial magnetic orientation of FIG. 5D). Another considerationcan be the coefficient of friction between the surfaces of the devicescontaining primary and secondary alignment components; lower frictiondecreases resistance to the shear force exerted by the annular magneticalignment components.

A radially-symmetric closed-loop magnetic alignment system (e.g.,magnetic alignment system 500 of FIGS. 5A and 5B) can provide accurateand robust alignment in the axial and lateral directions. Further,because of the radial symmetry, the alignment system does not have apreferred rotational orientation in the lateral plane about the axis;the shear force profile can be the same regardless of relativerotational orientation of the electronic devices being aligned.

1.4.2. Alternating Radial Orientation

In some embodiments, a closed-loop magnetic alignment system can bedesigned to provide one or more preferred rotational orientations. FIG.7 shows a simplified top-down view of a secondary alignment component718 according to some embodiments. Secondary alignment component 718includes sectors 728 a-h having radial magnetic orientations as shown bymagnetic polarity indicators 717 a-h. Each of sectors 728 a-h caninclude one or more secondary arcuate magnets. In this example,secondary magnets in sectors 728 b, 728 d, 728 f, and 728 h each have anorth magnetic pole oriented toward the radially outward side and asouth magnetic pole toward the radially inward side, while secondarymagnets in sectors 728 a, 728 c, 728 e, and 728 g each have a northmagnetic pole oriented toward the radially inward side and a southmagnetic pole toward the radially outward side. In other words, magnetsin adjacent sectors 728 a-h of secondary alignment component 718 havealternating magnetic orientations.

A complementary primary alignment component can have sectors withcorrespondingly alternating magnetic orientations. For example, FIG. 8Ashows a perspective view of a magnetic alignment system 800 according tosome embodiments. Magnetic alignment system 800 includes a secondaryalignment component 818 having alternating radial magnetic orientations(e.g., as shown in FIG. 7 ) and a complementary primary alignmentcomponent 816. Some of the arcuate sections of magnetic alignment system800 are not shown in order to reveal internal structure; however, itshould be understood that magnetic alignment system 800 can be acomplete annular structure. Also shown are components 802, which caninclude, for example, inductive coil assemblies or other componentslocated within the central region of primary annular alignment component816 and/or secondary annular alignment component 818. Magnetic alignmentsystem 800 can be a closed-loop magnetic alignment system similar tomagnetic alignment system 300 described above and can include arcuatesectors 801 b, 801 c of alternating magnetic orientations, with eacharcuate sector 801 b, 801 c including one or more arcuate magnets ineach of primary annular alignment component 816 and secondary annularalignment component 818. In some embodiments, the closed-loopconfiguration of magnetic alignment system 800 can reduce or preventmagnetic field leakage that may affect component 802. Like magneticalignment system 500, magnetic alignment system 800 can include a gap803 between two sectors.

FIG. 8B shows an axial cross-section view through one of arcuate sectors801 b, and FIG. 8C shows an axial cross-section view through one ofarcuate sectors 801 c. Arcuate sector 801 b includes a primary magnet826 b and a secondary magnet 828 b. As shown by orientation indicator817 b, secondary magnet 828 b has a magnetic polarity oriented in aradially outward direction, i.e., the north magnetic pole is toward theradially outward side of magnetic alignment system 800. Like primarymagnets 326 described above, primary magnet 826 b includes an innerarcuate magnetic region 852 b, an outer arcuate magnetic region 854 b,and a central non-magnetized region 856 b (which can include, e.g., anair gap or a region of nonmagnetic or non-magnetized material). Innerarcuate magnetic region 852 b has a magnetic polarity oriented axiallysuch that the north magnetic pole is toward secondary magnet 828 b, asshown by indicator 853 b, while outer arcuate magnetic region 854 b hasan opposite magnetic orientation, with the south magnetic pole orientedtoward secondary magnet 828 b, as shown by indicator 855 b. As describedabove with reference to FIG. 3B, the arrangement of magneticorientations shown in FIG. 8B results in magnetic attraction betweenprimary magnet 826 b and secondary magnet 828 b.

As shown in FIG. 8C, arcuate sector 801 c has a “reversed” magneticorientation relative to arcuate sector 801 b. Arcuate sector 801 cincludes a primary magnet 826 c and a secondary magnet 828 c. As shownby orientation indicator 817 c, secondary magnet 828 c has a magneticpolarity oriented in a radially inward direction, i.e., the northmagnetic pole is toward the radially inward side of magnetic alignmentsystem 800. Like primary magnets 326 described above, primary magnet 826c includes an inner arcuate magnetic region 852 c, an outer arcuatemagnetic region 854 c, and a central non-magnetized region 856 c (whichcan include, e.g., an air gap or a region of nonmagnetic ornon-magnetized material). Inner arcuate magnetic region 852 c has amagnetic polarity oriented axially such that the south magnetic pole istoward secondary magnet 828 c, as shown by indicator 853 c, while outerarcuate magnetic region 854 c has an opposite magnetic orientation, withthe north magnetic pole oriented toward secondary magnet 828 c, as shownby indicator 855 c. As described above with reference to FIG. 3B, thearrangement of magnetic orientations shown in FIG. 8C results inmagnetic attraction between primary magnet 826 c and secondary magnet828 c.

An alternating arrangement of magnetic polarities as shown in FIGS. 7and 8A-8C can create a “ratcheting” feel when secondary alignmentcomponent 818 is aligned with primary alignment component 816 and one ofalignment components 816, 818 is rotated relative to the other about thecommon axis. For instance, as secondary alignment component 816 isrotated relative to primary alignment component 816, eachradially-outward magnet 828 b alternately comes into proximity with acomplementary magnet 826 b of primary alignment component 816, resultingin an attractive magnetic force, or with an anti-complementary magnet826 c of primary alignment component 816, resulting in a repulsivemagnetic force. If primary magnets 826 b, 826 c and secondary magnets828 b, 828 c have the same angular size and spacing, in any givenorientation, each pair of magnets will experience similar net(attractive or repulsive) magnetic forces such that alignment is stableand robust in rotational orientations in which complementary magnetpairs 826 b, 828 b and 826 c, 828 c are in proximity. In otherrotational orientations, a torque toward a stable rotational orientationcan be experienced.

In the examples shown in FIGS. 7 and 8A-8C, each sector includes onemagnet, and the direction of magnetic orientation alternates with eachmagnet. In some embodiments, a sector can include two or more magnetshaving the same direction of magnetic orientation. For example, FIG. 9Ashows a simplified top-down view of a secondary alignment component 918according to some embodiments. Secondary alignment component 918includes secondary magnets 928 b with radially outward magneticorientations and secondary magnets 928 c with radially inwardorientations, similarly to secondary alignment component 818 describedabove. In this example, the magnets are arranged such that a pair ofoutwardly-oriented magnets 928 b (forming a first sector 901) areadjacent to a pair of inwardly-oriented magnets 928 c (forming a secondsector 903 adjacent to first sector 901). The pattern of alternatingsectors (with two magnets per sector) repeats around the circumferenceof secondary alignment component 918. Similarly, FIG. 9B shows asimplified top-down view of another secondary alignment component 918′according to some embodiments. Secondary alignment component 918′includes secondary magnets 928 b with radially outward magneticorientations and secondary magnets 928 c with radially inwardorientations. In this example, the magnets are arranged such that agroup of four radially-outward magnets 928 b (forming a first sector911) is adjacent to a group of four radially-inward magnets 928 c(forming a second sector 913 adjacent to first sector 911). The patternof alternating sectors (with four magnets per sector) repeats around thecircumference of secondary alignment component 918′. Although not shownin FIGS. 9A and 9B, the structure of a complementary primary alignmentcomponent for secondary alignment component 918 or 918′ should beapparent in view of FIGS. 8A-8C. A shear force profile for the alignmentcomponents of FIGS. 9A and 9B can be similar to the ratcheting profiledescribed above, although the number of rotational orientations thatprovide stable alignment will be different.

1.4.3. Other Magnetic Orientations

In other embodiments, a variety of force profiles can be created bychanging the magnetic orientations of different sectors within theprimary and/or secondary alignment components. As just one example, FIG.10 shows a simplified top-down view of a secondary alignment component1018 according to some embodiments. Secondary alignment component hassectors 1028 a-h with sector-dependent magnetic orientations as shown bymagnetic polarity indicators 1017 a-h. In this example, secondaryalignment component 1018 can be regarded as bisected by bisector line1001, which defines two halves of secondary alignment component 1018. Ina first half 1003, sectors 1028 e-h have magnetic polarities orientedradially outward, similarly to examples described above.

In the second half 1005, sectors 1028 a-d have magnetic polaritiesoriented substantially parallel to bisector line 1001 rather thanradially. In particular, sectors 1028 a and 1028 b have magneticpolarities oriented in a first direction parallel to bisector line 1001,while sectors 1028 c and 1028 d have magnetic polarities oriented in thedirection opposite to the direction of the magnetic polarities ofsectors 1028 a and 1028 b. A complementary primary alignment componentcan have an inner annular region with magnetic north pole orientedtoward secondary alignment component 1018, an outer annular region withmagnetic north pole oriented away from secondary alignment component1018, and a central non-magnetized region, providing a closed-loopmagnetic orientation as described above. The asymmetric arrangement ofmagnetic orientations in secondary alignment component 1018 can modifythe shear force profile such that secondary alignment component 1018generates less shear force resisting motion in the direction towardsecond half 1005 (upward in the drawing) than in the direction towardfirst half 1003 (downward in the drawing). In some embodiments, anasymmetrical arrangement of this kind can be used where the primaryalignment component is mounted in a docking station and the secondaryalignment component is mounted in a portable electronic device thatdocks with the docking station. Assuming secondary annular alignmentcomponent 1018 is oriented in the portable electronic device such thathalf-annulus 1005 is toward the top of the portable electronic device,the asymmetric shear force can facilitate an action of sliding theportable electronic device downward to dock with the docking station orupward to remove it from the docking station, while still providing anattractive force to draw the portable electronic device into a desiredalignment with the docking station.

In the embodiments described above, the secondary annular magneticalignment component has a magnetic orientation that is generally alignedin the transverse plane. In some alternative embodiments, a secondaryannular magnetic alignment component can instead have a quad-poleconfiguration similar to that of primary annular magnetic alignmentcomponent 316 of FIGS. 3A and 3B, with or without a DC shield (which, ifpresent, can be similar to DC shield 314 of FIGS. 3A and 3B) on thedistal surface of the secondary arcuate magnets. Using quad-polemagnetic configurations in both the primary and secondary alignmentcomponents can provide a closed-loop DC magnetic flux path and a strongsensation of “snappiness”; however, the thickness of the secondarymagnetic alignment component may need to be increased to accommodate thequad-pole magnets and DC shield, which may increase the overallthickness of a portable electronic device that houses the secondarymagnetic alignment component. To reduce thickness, the DC shield on thedistal surface of the secondary alignment component can be omitted;however, omitting the DC shield may result in increased flux leakageinto neighboring components.

It will be appreciated that the foregoing examples are illustrative andnot limiting. Sectors of a primary and/or secondary alignment componentcan include magnetic elements with the magnetic polarity oriented in anydesired direction and in any combination, provided that the primary andsecondary alignment components of a given magnetic alignment system havecomplementary magnetic orientations that exert forces toward the desiredposition of alignment. Different combinations of magnetic orientationsmay create different shear force profiles, and the selection of magneticorientations may be made based on a desired shear force profile (e.g.,high snappiness), avoidance of DC flux leakage into other components,and other design considerations.

1.5. Annular Magnetic Alignment Components with Gaps

In examples described above, the primary alignment component andsecondary alignment component have annular shapes. As described above(e.g., with reference to FIG. 3A), the annulus can be completely closed.In other embodiments (e.g., as shown in FIGS. 5A and 8A), a primary orsecondary annular alignment component can include one or more gaps,where each gap can be a section of an annulus where magnetic material(or indeed any material) is absent.

FIG. 11 illustrates an example of an alignment component 1118 (which canbe a primary or secondary annular magnetic alignment component) having agap according to some embodiments. As shown, alignment component 1118can include a number of arcuate magnets 1128 forming an annular shape.In this embodiment, a gap 1101 between two magnets is created byomitting one of arcuate magnets 1128. More generally, a gap such as gap1101 can be created using various techniques. For example, the angle ϕsubtended by each arcuate magnet can be selected such that 360°/ϕ is notan integer. Thus, the size of gap 1101 may be equal to or smaller than(or larger than) the size of an arcuate magnet 1128. In variousembodiments of a magnetic alignment system, a gap such as gap 1101 maybe formed in either or both of a secondary alignment component and aprimary alignment component, and the size, number, and location of gapscan be different between the primary and secondary alignment components.To provide reliable magnetic alignment, the size of gap 1101 or othergaps can be limited, e.g., to 20° of arc or less.

In some embodiments, a gap such as gap 1101 may provide a convenientpath for electrical connections to components located in interior region1103 inboard of alignment component 1118. For example, as describedabove, an inductive coil (or other electronic component) may be disposedin interior region 1103, and gap 1101 in alignment component 1118 mayprovide a convenient path for electrical connections between theinductive coil (or other component) and a battery (or other components)located outboard of alignment component 1118. It should be understoodthat electrical connections can also be made by routing connection pathsover or under magnets 1128 (into or out of the plane of FIG. 11 );however, routing connection paths over or under the magnets may resultin increased thickness of the device in which alignment component 1118is disposed.

It should be understood that a gap such as gap 1101 can be included in aprimary alignment component, a secondary alignment component, or both.In some embodiments where gaps are provided in both the primaryalignment component and the secondary alignment component, the presenceof the gaps may alter the shear force profile in a manner that creates apreferred rotational orientation. The extent to which a preferredorientation arises may depend on the size of the gaps and the particularconfiguration of magnets.

1.6. Portable Electronic Devices Incorporating Magnetic AlignmentComponents

FIGS. 12A and 12B show simplified rear views of portable electronicdevices incorporating magnetic alignment components according to someembodiments. In the examples shown, the portable electronic devicesincorporate secondary magnetic alignment components having a radialmagnetic orientation, which can allow for a thinner device profile;however, it should be understood that a portable electronic device caninstead incorporate a primary magnetic alignment component.

FIG. 12A shows a smart phone 1200 as an example of a portable electronicdevice that can incorporate a magnetic alignment component according tosome embodiments. Smart phone 1200 can support a variety of computingand communication activities and can draw operating power from anonboard battery (not shown). In some embodiments, the battery can berecharged using wireless power transfer. For example, smart phone 1200can include a coil assembly 1210, which can be configured as aninductive receiver coil for wireless power transfer. Such time-varyingmagnetic fields can be provided by a transmitter coil in a wirelesscharger device (not shown in FIG. 12A). In addition or instead, coilassembly 1210 may be operable as an inductive transmitter coil forwireless power transfer and may be operable to generate time-varyingmagnetic fields that can be used to charge an accessory device such as awireless headset, an external battery, or another portable electronicdevice (e.g., another smart phone). Coil assembly 1210 can include aninductive receiver coil (e.g., a wound coil of electrically conductivewire) coupled to a power storage device (e.g., a battery) or powerconsuming device. In some embodiments, coil assembly 1210 can alsoinclude electromagnetic shielding (e.g., one or more pieces of ferrite)placed over the distal surface, inner annular surface, and/or outerannular surface of the coil.

For optimal wireless charging performance, it is desirable to align coil1210 with a coil in the transmitting (or receiving) device. Annularmagnetic alignment component 1218 can be, for example, an implementationof any of the secondary magnetic alignment components described aboveand can include an annular arrangement of magnets 1228 with interfaces1232, which can be air gaps or surfaces where adjacent magnets contactone another. The magnetic polarities of magnets 1228 can be oriented invarying directions in the lateral plane, e.g., in a radial direction asdescribed above with reference to FIG. 4 . In the example shown,magnetic alignment component 1218 includes a gap 1201, which can provideelectrical connection paths for wires (or conductive traces) to connectbetween coil 1210 and components outboard of magnetic alignmentcomponent 1218. Coil 1210 can be optimized to support wireless powertransfer between devices.

In some embodiments, a magnetic alignment component such as component1218 can be modified to fit portable electronic devices of differentsizes while preserving a constant outer diameter and radial width of theannulus. By way of example, FIG. 12B shows a smart phone 1200′ asanother example of a portable electronic device that can incorporate amagnetic alignment component according to some embodiments. Like smartphone 1200 of FIG. 12A, smart phone 1200′ can support a variety ofcomputing and communication activities and may draw operating power froman onboard battery (not shown). One difference between smart phone 1200and smart phone 1200′ can be that smart phone 1200′ has a smaller formfactor than smart phone 1200. For instance smart phone 1200′ may benarrower (in the x direction) and/or shorter (in the y direction) thansmart phone 1200. However, it may be desirable for these smart phones ofdifferent form factors to interoperate with the same wireless chargerdevices and/or other accessories. Accordingly, smart phone 1200′ caninclude a wireless charging coil 1210′ that can be identical to wirelesscharging coil 1210 of smart phone 1200.

To provide alignment of coil 1210′ with a coil in another device, smartphone 1200′ can include a magnetic alignment component 1218′. Magneticalignment component 1218′ can be for example, an implementation of anyof the secondary magnetic alignment components described above and caninclude an annular arrangement of arcuate magnets 1228′ with interfaces1232′, which can be air gaps or surfaces where adjacent magnets 1228′contact one another. The magnetic polarities of magnets 1228′ can beoriented in varying directions in the lateral plane, e.g., in a radialdirection as described above.

In the example shown, to accommodate the narrower width of smart phone1200′ magnetic alignment component 1218′ includes diametrically opposedgaps 1201 a, 1201 b. In addition to decreasing the width (in the xdirection) of magnetic alignment component 1218′, gaps 1201 a and/or1201 b can also provide electrical connection paths for wires (orconductive traces) to connect between coil 1210′ and components outboardof magnetic alignment component 1218′. In some embodiments, the arcuatemagnet sections 1228′ adjacent to gaps 1201 a, 1201 b can have beveledcorners 1229 a-b and 1231 a-b, which can further reduce the width ofalignment component 1218′ without reducing the outer diameter.

It should be understood that smart phones 1200 and 1200′ are justexamples, and a variety of portable electronic devices having a range ofdifferent form factors can accommodate an annular alignment component ofa given diameter and width. Further, while FIGS. 12A and 12B showalignment components 1218, 1218′ and coils 1210, 1210′ on the rear ofsmart phones 1200, 1200′, it should be understood that these componentscan be inside the rear housing of smart phones 1200, 1200′ and that therear housing may be opaque so that alignment components 1218, 1218′ andcoils 1210, 1210′ need not be visible to users.

1.7. Wireless Charger Devices Incorporating Magnetic AlignmentComponents

FIG. 13 shows a simplified view of a wireless charger device 1300incorporating a magnetic alignment component according to someembodiments. In the example shown, the wireless charger deviceincorporates a primary alignment component; however, it should beunderstood that a wireless charger device can instead incorporate asecondary magnetic alignment component.

Wireless charger device 1300 can support inductive power transfer forcharging a portable electronic device (such as smart phone 1200 of FIG.12A or smart phone 1200′ of FIG. 12B). In this example, wireless chargerdevice 1300 has a housing 1302 surrounding a transmitter coil assembly1312. Although not shown in FIG. 13 , it should be understood thattransmitter coil assembly 1312 can include an inductive transmitter coilhaving wires that can be connected to an external power source (e.g.,via cable 1304). In some embodiments, transmitter coil assembly 1312 canalso include electromagnetic shielding (e.g., one or more pieces offerrite placed over the distal surface, inner annular surface, and/orouter annular surface of the transmitter coil and/or a thin layer ofmetal placed over the proximal surface of the transmitter coil to reduceparasitic electric fields). Control circuitry to control the transmittercoil can be disposed within housing 1302 or elsewhere as desired. Aprimary magnetic alignment component 1316 is disposed around transmittercoil assembly 1312.

Components of wireless charger device 1300 can be enclosed in housing1302, which can be made of aluminum, plastic, ceramic, or other durablematerial. Housing 1302 is shown as puck-shaped; however, other shapescan also be used. For instance, housing 1302 can be rectangular,elliptical, or any other shape that provides a charging surface. In someembodiments, housing 1302 can be a two-piece housing that includes anenclosure for the distal and side surfaces of wireless charger device1300 and a top cap covering the proximal surface of transmitter coilassembly 1312. The top cap (not shown in FIG. 13 ) can be made ofceramic or other material that is permeable to electromagnetic fields,while the enclosure can be made of aluminum, plastic or other materials.The top cap and enclosure can be sealed together using an appropriateadhesive. Although FIG. 13 shows a view into the interior of wirelesscharger device 1300, it should be understood that housing 1302 can beopaque. Housing 1302 can include an opening to permit connection ofcable 1304 to transmitter coil assembly 1312. In some embodiments, oneend of cable 1304 is captively coupled to electronic components oftransmitter coil assembly 1312 while the other end of cable 1304 (notshown) is coupled to a plug connector (e.g., a USB type A or USB-Cconnector) that can be used to draw power from the grid or other powersource via an adapter.

For optimal wireless charging performance, it is desirable to align thetransmitter coil of coil assembly 1312 with a corresponding coil in areceiving device such as smart phone 1200. Magnetic alignment component1316 can be, for example, an implementation of any of the primarymagnetic alignment components described above and can include an annulararrangement of magnets 1326 with interfaces 1330 between adjacentmagnets 1326, which can be air gaps or surfaces where adjacent magnets1326 contact one another. Magnets 1326 can provide a closed loopconfiguration as described above; for instance, each magnet 1326 caninclude an inner arcuate region having an axial magnetic orientation ina first direction, an outer arcuate region having an axial magneticorientation in a second direction opposite the first direction, and acentral arcuate region having no distinct magnetic orientation. In theexample shown, magnetic alignment component 1316 includes a gap 1301,which can provide electrical connection paths for wires (or conductivetraces) to connect between coil assembly 1312 and cable 1304 withoutadding to the axial thickness of wireless charger device 1300. Coilassembly 1312 can be optimized to support wireless power transferbetween devices.

In various embodiments, primary magnetic alignment component 1316 can beused to facilitate alignment between wireless charger device 1300 and avariety of different portable electronic devices having different formfactors (e.g., including portable electronic device 1200 and portableelectronic device 1200′). As long as the portable electronic devicebeing aligned with primary magnetic alignment component 1316 includes acomplementary secondary alignment component having an annular shapematching primary alignment component 1316 and a magnetic fieldorientation complementary to primary alignment component 1316, primaryalignment component 1316 can facilitate alignment of wireless chargerdevice 1300 with the portable electronic device, regardless of any otherdimensions of either device. It should also be understood that someembodiments of wireless charger device 1300 can be used to charge aportable electronic device that does not have a magnetic alignmentcomponent; however, in such instances, primary alignment component 1316might not facilitate optimal alignment with the portable electronicdevice, and the user would need to align the devices using othertechniques (e.g., manual adjustment based on charging performance orplacing the devices in a cradle that holds the devices such that theirrespective charging coils are in alignment).

1.8. Wireless Charging Systems with Magnetic Alignment

FIG. 14A shows a simplified perspective view of a system 1400 includingportable electronic device 1200 (of FIG. 12A) in alignment with wirelesscharger device 1300 (of FIG. 13 ) according to some embodiments. In FIG.14A, portions of wireless charger device 1300 are shown using dashedlines to avoid obscuring other details. As shown, wireless chargerdevice 1300 can be placed with its charging (or proximal) surfaceagainst the rear (or proximal) surface 1403 of portable electronicdevice 1200. When the devices are placed in this arrangement, secondaryalignment component 1218 in portable electronic device 1200 can attractand hold primary magnetic alignment component 1316 of wireless chargerdevice 1300 in alignment so that transmitter coil assembly 1312 ofwireless charger device 1300 is aligned with coil assembly 1210 ofportable electronic device 1200. As shown, wireless charger device 1300can have any rotational orientation about an axis defined by the centersof primary magnetic alignment component 1316 and secondary magneticalignment component 1218; for instance gap 1201 in secondary magneticalignment component 1218 need not align with gap 1301 in primarymagnetic alignment component 1316.

FIG. 14B shows a simplified partial cross section view of system 1400according to some embodiments. Portable electronic device 1200 has arear housing 1402 (which can be made of a material such as glass orplastic that is permeable to electromagnetic fields and to DC magneticfields) and a front housing 1404 (which can include a touch screendisplay). Coil assembly 1210 can include an inductive receiver coil 1410(which can be made, e.g., of stranded wire wound into a coil) andshielding 1412 (which can include, e.g., a ferrimagnetic shield).Secondary magnet 1428 forms a portion of secondary magnetic alignmentcomponent 1218 and can have a magnetic field oriented in a radiallyinward direction (as shown by the arrow). It should be understood that,although alignment component 1218 is shown in FIG. 14A, rear housing1402 can be opaque and alignment component 1218 need not be visible to auser.

Wireless charger device 1300 has a housing 1302 that includes asingle-piece enclosure 1406 forming distal and side surfaces of housing1302 and a top cap 1408 forming a proximal surface of housing 1302. Asdescribed above, enclosure 1406 and top cap 1408 can be made of the samematerial or different materials, and top cap 1408 can be made of amaterial that is permeable to AC electromagnetic fields and to DCmagnetic fields. Transmitter coil assembly 1312 can include an inductivetransmitter coil 1416 (which can be made, e.g., of stranded wire woundinto a coil) and electromagnetic shielding 1415 (which can include,e.g., a ferrimagnetic shield). Primary magnet 1426 forms a portion ofprimary magnetic alignment component 1316 and can include an innerarcuate region 1452 having a magnetic field oriented in a first axialdirection, an outer arcuate region 1454 having a magnetic field orientedin a second axial direction opposite the first axial direction, and anon-magnetized central arcuate region 1456. As described above, a DCshield 1414 can be disposed on the distal surface of primary magnet1426. It should be understood that, although alignment component 1316 isshown in FIG. 14A, housing 1302 can be opaque and alignment component1316 need not be visible to a user.

When aligned, primary magnet 1426 and secondary magnet 1428 produce aclosed-loop magnetic flux as shown by lines 1440. Magnetic flux 1440 canattract primary annular alignment component 1318 and secondary annularalignment component 1216 into alignment such that the respective centersof primary annular alignment component 1318 and secondary annularalignment component 1216 are aligned along a common axis. Sincetransmitter coil 1416 is fixed in a position concentric with primaryalignment component 1316 and receiver coil 1410 is fixed in positionconcentric with secondary alignment component 1218, a result of aligningprimary annular alignment component 1318 and secondary annular alignmentcomponent 1216 along a common axis is that transmitter coil 1416 andreceiver coil 1410 are also aligned along a common axis, therebyenabling efficient wireless power transfer. For instance, transmittercoil 1416 can be driven with an alternating current to generatetime-varying magnetic fields that induce a time-varying current inreceiver coil 1416. Electromagnetic shielding (e.g., shielding 1415 and1412) can confine the AC fields to the immediate vicinity of coils 1416and 1410.

In particular, some embodiments provide a gap region 1411 betweensecondary magnet 1428 and receiver coil assembly 1210 that mayexperience low DC magnetic flux and may also experience low ACelectromagnetic fields due to electromagnetic shielding 1412 around coil1410. Similarly, some embodiments provide a gap region 1413 betweenprimary magnet 1426 and transmitter coil assembly 1312 that mayexperience low DC magnetic flux and may also experience low ACelectromagnetic fields due to electromagnetic shielding 1418 aroundtransmitter coil 1416. It is noted that a similar gap region may becreated when using a z-pole magnetic alignment system of the kind shownin FIG. 2 ; however, a larger space between the charging coils andmagnets would be required.

As can be appreciated with reference to FIG. 14B, each secondaryalignment magnet 1428 of secondary alignment component 1218 can have athin axial dimension so that secondary alignment component 1218 does notrequire an increased thickness of portable electronic device 1200. Forinstance, the axial thickness of each secondary alignment magnet 1428can be less than or equal to the thickness of receiver coil assembly1210 (including coil 1410 and shielding 1412). Primary alignmentcomponent 1426 can have a thicker axial dimension, e.g., occupying allof the axial space between enclosure 1406 and top cap 1408. In someembodiments, primary alignment component 1426 can also have a radialwidth that is slightly larger than a radial width of secondary alignmentcomponent 1428.

FIG. 15 is a block diagram illustrating an exemplary wireless chargingsystem 1500 including a portable electronic device 1504 (which can be,e.g., portable electronic device 1200 or any other portable electronicdevice described herein) and a wireless charger device 1502 (which canbe, e.g., wireless charger device 1300 or any other wireless chargerdevice described herein) that can be aligned together via a magneticalignment system 1506 according to some embodiments. Magnetic alignmentsystem 1506 can include a primary alignment component 1516 withinwireless charger device 1502 and a secondary alignment component 1518within portable electronic device 1504. Primary alignment component 1516and secondary alignment component 1516 can be constructed according toany of the embodiments described herein. Portable electronic device 1504can also include a computing system 1541 coupled to a memory bank 1542.Computing system 1541 can include control circuitry configured toexecute instructions stored in memory bank 1542 for performing variousfunctions for operating portable electronic device 1504. The controlcircuitry can include one or more programmable integrated logiccircuits, such as microprocessors, central processing units (CPUs),graphics processing units (GPUs), field programmable gate arrays(FPGAs), or the like.

Computing system 1541 can also be coupled to a user interface system1543, a communication system 1544, and a sensor system 1545 for enablingportable electronic device 1504 to perform one or more functions. Forinstance, user interface system 1543 can include a display, speaker,microphone, actuator for enabling haptic feedback, and one or more inputdevices such as a button, switch, capacitive screen for enabling thedisplay to be touch sensitive, and the like. Communication system 1544can include wireless telecommunication components, near-fieldcommunication (NFC) components, Bluetooth components, and/or Wi-Ficomponents for enabling portable electronic device 1504 to make phonecalls, interact with wireless accessories, and access the Internet.Sensor system 1545 can include light sensors, accelerometers,gyroscopes, temperature sensors, magnetometers, and/or any other type ofsensor that can measure a parameter of an external entity and/orenvironment.

All of these electrical components require a power source to operate.Accordingly, portable electronic device 1504 also includes a battery1546 that can discharge stored energy to power the electrical componentsof portable electronic device 1504. To replenish the energy dischargedto power the electrical components, portable electronic device 1504includes charging circuitry 1547 and an inductive coil 1510 that canreceive power from wireless charger device 1502 coupled to an externalpower source 1522.

Wireless charger device 1502 can include a transmitter coil 1512 forgenerating time-varying magnetic flux capable of inducing an electricalcurrent in coil 1510 of portable electronic device 1504. The inducedcurrent can be used by charging circuitry 1547 to charge battery 1546.Wireless charger device 1502 can further include a computing system 1521coupled to a communication system 1524 and wireless charging circuitry1523. Wireless charging circuitry can include circuit components toconvert standard AC power having a first set of voltage and frequencycharacteristics (e.g., standard AC wall power) to AC power suitable foroperating coil 1510. Suitable circuit components, including rectifiers(AC-to-DC converters), boost circuits (DC-to-DC voltage boostingcircuits), inverters (DC-to-AC converters), and the like, are known inthe art. Computing system 1521 can include logic circuitry (such as amicroprocessor, microcontroller, FPGA, or the like) configured tocontrol the operation of wireless charger device 1502, such as tocontrol wireless charging circuitry 1523 to use power received fromexternal power source 1522 to generate time-varying magnetic flux toinduce current in coil 1510 to charge portable electronic device 1504.In some embodiments, computing system 1521 can implement functionalityconfirming to the Qi standard for wireless charging (promulgated by theWireless Power Consortium).

In some embodiments, components implementing computing system 1521 andwireless charging circuitry 1523 can be disposed within the housing thatholds coil 1512 and primary alignment component 1516 (e.g., withinpuck-shaped housing 1302 of FIGS. 13 and 14A-14B). In other embodiments,some or all of the components implementing computing system 1521 andwireless charging circuitry 1523 can be disposed elsewhere, e.g., at thedistal end of cable 1304 in FIGS. 13 and 14A. For example, the logiccircuitry implementing computing system 1521 can be disposed withinhousing 1302 while wireless charging circuitry 1532 is disposed in aboot of a plug connector at the distal end of cable 1304. (In this case,cable 1304 can provide AC power to wireless charger device 1300.) Asanother example, the logic circuitry implementing computing system 1521and circuit components implementing portions of wireless chargingcircuitry 1523 can be disposed within housing 1302 while circuitcomponents implementing other portions of wireless charging circuitry1523 are disposed in a boot of a plug connector at the distal end ofcable 1304. For instance, an inverter may be disposed within housing1302 while a rectifier and boost circuit are disposed in the boot. (Inthis case, cable 1304 can provide DC power to wireless charger device1300.)

While system 1500 is described with reference to particular blocks, itis to be understood that these blocks are defined for convenience ofdescription and are not intended to imply a particular physicalarrangement of component parts. The blocks need not correspond tophysically distinct components, and the same physical components can beused to implement aspects of multiple blocks. Blocks can be configuredto perform various operations, e.g., by programming a processor orproviding appropriate control circuitry, and various blocks might ormight not be reconfigurable depending on how the initial configurationis obtained. Embodiments of the present invention can be realized in avariety of apparatus including electronic devices that use using anycombination of circuitry and software to enable wireless chargingoperations and/or other operations where physical alignment betweendevices is desired.

2. Rotational Alignment Components

In various embodiments described above, a magnetic alignment system canprovide robust alignment in a lateral plane and may or may not providerotational alignment. For example, radially symmetric magnetic alignmentsystem 500 of FIGS. 5A-5B may not define a preferred rotationalorientation. Radially alternating magnetic alignment system 800 of FIGS.8A-8C can define multiple equally preferred rotational orientations. Forsome applications, such as alignment of a portable electronic devicewith a wireless charger puck or mat, rotational orientation may not be aconcern. In other applications, such as alignment of a portableelectronic device in a docking station or other mounting accessory, aparticular rotational alignment may be desirable. Accordingly, in someembodiments an annular magnetic alignment component can be augmentedwith one or more rotational alignment components positioned outboard ofand spaced apart from the annular magnetic alignment components. Therotational alignment component(s) can help guide devices into a targetrotational orientation relative to each other.

FIG. 16 shows an example of a magnetic alignment system with an annularalignment component and a rotational alignment component according tosome embodiments. FIG. 16 shows respective proximal surfaces of aportable electronic device 1604 and an accessory 1602. In this example,primary alignment components of the magnetic alignment system areincluded in an accessory device 1602, and secondary alignment componentsof the magnetic alignment system are included in a portable electronicdevice 1604. Portable electronic device 1604 can be, for example, asmart phone whose front surface provides a touchscreen display and whoseback surface is designed to support wireless charging. Accessory device1602 can be, for example, a charging dock that supports portableelectronic device 1604 such that its display is visible and accessibleto a user. For instance, accessory device 1602 can support portableelectronic device 1604 such that the display is vertical or at aconveniently tilted angle for viewing and/or touching. In the exampleshown, accessory device 1602 supports portable electronic device 1604 ina “portrait” orientation (shorter sides of the display at the top andbottom); however, in some embodiments accessory device 1602 can supportportable electronic device 1604 in a “landscape” orientation (longersides of the display at the top and bottom). Accessory device 1602 canalso be mounted on a swivel, gimbal, or the like, allowing the user toadjust the orientation of portable electronic device 1604 by adjustingthe orientation of accessory device 1602.

As described above, components of a magnetic alignment system caninclude a primary annular alignment component 1616 disposed in accessory1602 and a secondary annular alignment component 1618 disposed inportable electronic device 1604. Primary annular alignment component1616 can be similar or identical to any of the primary alignmentcomponents described above. For example, primary annular alignmentcomponent 1616 can be formed of arcuate magnets 1626 arranged in anannular configuration. Although not shown in FIG. 16 , one or more gapscan be provided in primary annular alignment component 1616, e.g., byomitting one or more of arcuate magnets 1626 or by providing a gap atone or more interfaces 1630 between adjacent arcuate magnets 1626. Insome embodiments, each arcuate magnet 1626 can include an inner arcuateregion having a first magnetic orientation (e.g., axially oriented in afirst direction), an outer arcuate region having a second magneticorientation opposite the first magnetic orientation (e.g., axiallyoriented opposite the first direction), and a central non-magnetizedarcuate region between the inner and outer regions (as described above,the non-magnetized central region can include an air gap or anonmagnetic material). In some embodiments, primary annular alignmentcomponent 1616 can also include a DC shield (not shown) on the distalside of arcuate magnets 1626.

Likewise, secondary annular alignment component 1618 can be similar oridentical to any of the secondary alignment components described above.For example, secondary annular alignment component 1618 can be formed ofarcuate magnets 1628 arranged in an annular configuration. Although notshown in FIG. 16 , one or more gaps can be provided in secondary annularalignment component 1618, e.g., by omitting one or more arcuate magnets1628 or by providing a gap at one or more interfaces 1632 betweenadjacent magnets 1628. As described above, arcuate magnets 1628 canprovide radially-oriented magnetic polarities.

For instance, all sectors of secondary annular alignment component 1618can have a radially-outward magnetic orientation or a radially-inwardmagnetic orientation, or some sectors of secondary annular alignmentcomponent 1618 may have a radially-outward magnetic orientation whileother sectors of secondary annular alignment component 1618 have aradially-inward magnetic orientation.

As described above, primary annular alignment component 1616 andsecondary annular alignment component 1618 can provide shear forces thatpromote alignment in the lateral plane so that center point 1601 ofprimary annular alignment component 1616 aligns with center point 1603of secondary annular alignment component 1618. However, primary annularalignment component 1616 and secondary annular alignment component 1618might not provide torque forces that favor any particular rotationalorientation, such as portrait orientation.

Accordingly, in some embodiments, a magnetic alignment system canincorporate one or more rotational alignment components in addition tothe annular alignment components. The rotational alignment componentscan include one or more magnets that provide torque about the commonaxis of the (aligned) annular alignment components, so that a preferredrotational orientation can be reliably established. For example, asshown in FIG. 16, a primary rotational alignment component 1622 can bedisposed outboard of and spaced apart from primary annular alignmentcomponent 1616 while a secondary rotational alignment component 1624 isdisposed outboard of and spaced apart from secondary annular alignmentcomponent 1618. Secondary rotational alignment component 1624 can bepositioned at a fixed distance (y₀) from center point 1603 of secondaryannular alignment component 1618 and centered between the side edges ofportable electronic device 1604 (as indicated by distance x₀ from eitherside edge). Similarly, primary rotational alignment component 1622 canbe positioned at the same distance y₀ from center point 1601 of primaryannular alignment component 1616 and located at a rotational angle thatresults in a torque profile that favors the desired orientation ofportable electronic device 1604 relative to accessory 1602 whensecondary rotational alignment component 1624 is aligned with primaryrotational alignment component 1622. It should be noted that the samedistance y₀ can be applied in a variety of portable electronic deviceshaving different form factors, so that a single accessory can becompatible with a family of portable electronic devices. A longerdistance y₀ can increase torque toward the preferred rotationalalignment; however, the maximum distance y₀ may be limited by designconsiderations, such as the size of the smallest portable electronicdevice in a family of portable electronic devices that incorporatemutually compatible magnetic alignment systems.

According to some embodiments, each of primary rotational alignmentcomponent 1622 and secondary rotational alignment component 1624 can beimplemented using one or more magnets (e.g., rare earth magnets such asNdFeB) each of which has each been magnetized such that its magneticpolarity is oriented in a desired direction. In the example of FIG. 16 ,the magnets have rectangular shapes; however, other shapes (e.g.,rounded shapes) can be substituted. The magnetic orientations ofrotational alignment components 1622 and 1624 can be complementary sothat when the proximal surfaces of rotational alignment components 1622and 1624 are near each other, an attractive magnetic force is exerted.This attractive magnetic force can help to rotate portable electronicdevice 1604 and accessory 1602 into a preferred rotational orientationin which the proximal surfaces of rotational alignment components 1622and 1624 are aligned with each other. Examples of magnetic orientationsfor rotational alignment components 1622 and 1624 that can be used toprovide a desired attractive force are described below. In someembodiments, primary rotational alignment component 1622 and secondaryrotational alignment component 1624 can have the same lateral (xy)dimensions and the same thickness. The dimensions can be chosen based ona desired magnetic field strength and/or torque, the dimensions ofdevices in which the rotational alignment components are to be deployed,and other design considerations. In some embodiments, the lateraldimensions can be about 6 mm (x direction) by about 16 mm (y direction),and the thickness can be anywhere from about 0.3 mm to about 1.5 mm; theparticular dimensions can be chosen based on the sizes of the devicesthat are to be aligned. In some embodiments, the thickness of therotational alignment component for a given device can be chosen to matchthe thickness of an annular alignment component in that device. In someembodiments, each of primary rotational alignment component 1622 andsecondary rotational alignment component 1624 can be implemented usingtwo or more rectangular blocks of magnetic material positioned adjacentto each other. As in other embodiments, a small gap may be presentbetween adjacent magnets, e.g., due to manufacturing tolerances.

FIGS. 17A and 17B show an example of rotational alignment according tosome embodiments. In FIG. 17A, accessory 1602 is placed on the backsurface of portable electronic device 1604 such that primary annularalignment component 1616 and secondary alignment component 1618 arealigned with each other in the lateral plane such that, in the viewshown, center point 1601 of primary annular alignment component 1616overlies center point 1603 of secondary annular alignment component1618. A relative rotation is present such that rotational alignmentcomponents 1622 and 1624 are not aligned. In this configuration, anattractive force between rotational alignment components 1622 and 1624can urge portable electronic device 1604 and accessory 1602 toward atarget rotational orientation. In FIG. 17B, the attractive magneticforce between rotational alignment components 1622 and 1624 has broughtportable electronic device 1604 and accessory 1602 into the targetrotational alignment with the sides of portable electronic device 1604parallel to the sides of accessory 1602. In some embodiments, theattractive magnetic force between rotational alignment components 1622and 1624 can also help to hold portable electronic device 1604 andaccessory 1602 in a fixed rotational alignment.

Rotational alignment components 1622 and 1624 can have various patternsof magnetic orientations. As long as the magnetic orientations ofrotational alignment components 1622 and 1624 are complementary to eachother, a torque toward the target rotational orientation can be presentwhen the devices are brought into lateral alignment and close to thetarget rotational orientation. FIGS. 18A-21B show examples of magneticorientations for a rotational alignment component according to variousembodiments. While the magnetic orientation is shown for only onerotational alignment component, it should be understood that themagnetic orientation of a complementary rotational alignment componentcan be complementary to the magnetic orientation of shown.

FIGS. 18A and 18B show a perspective view and a top view of a rotationalalignment component 1824 having a “z-pole” configuration according tosome embodiments. It should be understood that the perspective view isnot to any particular scale and that the lateral (xy) dimensions andaxial (z) thickness can be varied as desired. As shown in FIG. 18A,rotational alignment component 1824 can have a uniform magneticorientation along the axial direction, as indicated by arrows 1805.Accordingly, as shown in FIG. 18B, a north magnetic pole (N) may benearest the proximal surface 1803 of rotational alignment component1824. A complementary z-pole alignment component can have a uniformmagnetic orientation with a south magnetic pole nearest the proximalsurface. The z-pole configuration can provide reliable alignment.

Other configurations can provide reliable alignment as well as astronger, or more salient, “clocking” sensation for the user. A“clocking sensation,” in this context, refers to a user-perceptibletorque about the common axis of the annular alignment components thaturges toward the target rotational alignment and/or resists smalldisplacements from the target rotational alignment. A greater variationof torque as a function of rotational angle can provide a more salientclocking sensation. Following are examples of magnetizationconfigurations for a rotational alignment component that can providemore salient clocking sensations than the z-pole configuration of FIGS.18A and 18B.

FIGS. 19A and 19B show a perspective view and a top view of a rotationalalignment component 1924 having a “quad-pole” configuration according tosome embodiments. It should be understood that the perspective view isnot to any particular scale and that the lateral (xy) dimensions andaxial (z) thickness can be varied as desired. As shown in FIG. 19A,rotational alignment component 1924 has a first magnetized region 1925with a magnetic orientation along the axial direction such that thenorth magnetic pole (N) is nearest the proximal (+z) surface 1903 ofrotational alignment component 1924 (as indicated by arrow 1905) and asecond magnetized region 1927 with a magnetic orientation opposite tothe magnetic orientation of the first region such that the southmagnetic pole (S) is nearest to proximal surface 1903 (as indicated byarrows 1907). Between magnetized regions 1925 and 1927 is a centralregion 1929 that is not magnetized. In some embodiments, rotationalalignment component 1924 can be formed from a single piece of magneticmaterial that is exposed to a magnetizer to create regions 1925, 1927,1929. Alternatively, rotational alignment component 1924 can be formedusing two pieces of magnetic material with a nonmagnetic material or anair gap between them. As shown in FIG. 19B, the proximal surface ofrotational alignment component 1924 can have one region having a “north”polarity and another region having a “south” polarity. A complementaryquad-pole rotational alignment component can have corresponding regionsof south and north polarity at the proximal surface.

FIGS. 20A and 20B show a perspective view and a top view of a rotationalalignment component 2024 having an “annulus design” configurationaccording to some embodiments. It should be understood that theperspective view is not to any particular scale and that the lateral(xy) dimensions and axial (z) thickness can be varied as desired. Asshown in FIG. 20A, rotational alignment component 2024 has an annularouter magnetized region 2025 with a magnetic orientation along the axialdirection such that the north magnetic pole (N) is nearest the proximal(+z) surface 2003 of rotational alignment component 2024 (as shown byarrows 2005) and an inner magnetized region 2027 with a magneticorientation opposite to the magnetic orientation of the first regionsuch that the south magnetic pole (S) is nearest to proximal surface2003. Between magnetized regions 2025 and 2027 is a neutral annularregion 2029 that is not magnetized. In some embodiments, rotationalalignment component 2024 can be formed from a single piece of magneticmaterial that is exposed to a magnetizer to create regions 2025, 2027,2029. Alternatively, rotational alignment component 2024 can be formedusing two or more pieces of magnetic material with a nonmagneticmaterial or an air gap between them. As shown in FIG. 20B, the proximalsurface of rotational alignment component 2024 can have an annular outerregion having a “north” polarity and an inner region having a “south”polarity. The proximal surface of a complementary annulus-designrotational alignment component can have an annular outer region of southpolarity and an inner region of north polarity.

FIGS. 21A and 21B show a perspective view and a top view of a rotationalalignment component 2124 having a “triple pole” configuration accordingto some embodiments. It should be understood that the perspective viewis not to any particular scale and that the lateral (xy) dimensions andaxial (z) thickness can be varied as desired. As shown in FIG. 21A,rotational alignment component 2124 has a central magnetized region 2125with a magnetic orientation along the axial direction such that thesouth magnetic pole (S) is nearest the proximal (+z) surface 2103 ofrotational alignment component 2124 (as shown by arrow 2105) and outermagnetized regions 2127, 2129 with a magnetic orientation opposite tothe magnetic orientation of central region 2125 such that the northmagnetic pole (N) is nearest to proximal surface 2103 (as shown byarrows 2107, 2109). Between central magnetized region 2125 and each ofouter magnetized regions 2127, 2129 is a neutral region 2131, 2133 thatis not strongly magnetized. In some embodiments, rotational alignmentcomponent 2124 can be formed from a single piece of magnetic materialthat is exposed to a magnetizer to create regions 2125, 2127, 2129.Alternatively, rotational alignment component 2124 can be formed usingthree (or more) pieces of magnetic material with nonmagnetic materialsor air gaps between them. As shown in FIG. 21B, the proximal surface mayhave a central region having a “south” polarity with an outer regionhaving “north” polarity to either side. The proximal surface of acomplementary triple-pole rotational alignment component can have acentral region of north polarity with an outer region of south polarityto either side.

It should be understood that the examples in FIGS. 18A-21B areillustrative and that other configurations may be used. The selection ofa magnetization pattern for a rotational alignment component can beindependent of the magnetization pattern of an annular alignmentcomponent with which the rotational alignment component is used.

In some embodiments, the selection of a magnetization pattern for arotational alignment component can be based on optimizing the torqueprofile. For example, as noted above, it may be desirable to provide asalient clocking sensation to a user when close to the desiredrotational alignment. The clocking sensation can be a result of torqueabout a rotational axis defined by the annular alignment components. Theamount of torque depends on various factors, including the distancebetween the axis and the rotational alignment component (distance y0 inFIG. 16 ) and the length (in the y direction as defined in FIG. 16 ) ofthe rotational alignment component, as well as the strength of themagnetic fields of the rotational alignment components (which may dependon the size of the rotational alignment components), the coefficient offriction between the surfaces being aligned, and whether the annularalignment components exert any torque toward a preferred rotationalorientation.

FIG. 22 shows a graph of torque as a function of angular rotation (indegrees) for an alignment system of the kind shown in FIG. 16 , fordifferent magnetization configurations of the rotational alignmentcomponent according to various embodiments. Angular rotation is definedsuch that zero degrees corresponds to the target rotational alignment(where the proximal surfaces of rotational angular components 1622 and1624 are in closest proximity, e.g., as shown in FIG. 17B). Torque isdefined such that positive (negative) values indicate force in thedirection of decreasing (increasing) rotational angle. For purpose ofgenerating the torque profiles, it is assumed that annular alignmentcomponents 1616 and 1618 are rotationally symmetric and do not exerttorque about the z axis defined by center points 1601 and 1603. Threedifferent magnetization configurations are considered. Line 2204corresponds to the quad-pole configuration of FIGS. 19A and 19B. Line2205 corresponds to the annulus design configuration of FIGS. 20A and20B. Line 2206 corresponds to the triple-pole configuration of FIGS. 21Aand 21B. As shown, the annulus design (line 2205) and triple-pole (line2206) configurations provide a sharper peak in the torque and thereforea more salient clocking sensation for the user, as compared to thequad-pole configuration (line 2204). In addition, the triple-poleconfiguration provides a stronger peak torque and therefore a moresalient clocking sensation than the annulus-design configuration. (Thetriple-pole configuration can also provide reduced flux leakage ascompared to other configurations.) It should be understood that thenumerical values in FIG. 22 are illustrative, and that torque in aparticular embodiment may depend on a variety of other factors inaddition to the magnetization configuration, such as the magnet volume,aspect ratio, and distance y0 from the center of the annular alignmentcomponent.

In the example shown in FIG. 16 , a single rotational alignmentcomponent is placed outboard of the annular alignment component at adistance y₀ from the center of the annular alignment component. Thisarrangement allows a single magnetic element to generate torque thatproduces a salient clocking sensation for a user aligning devices. Insome embodiments, other arrangements are also possible. For example,FIG. 23 shows a portable electronic device 2304 having an alignmentsystem 2300 with multiple rotational alignment components according tosome embodiments. In this example, alignment system 2300 includes anannular alignment component 2318 and a set of rotational alignmentcomponents 2324 positioned at various locations around the perimeter ofannular alignment component 2318. In this example, there are fourrotational alignment components 2324 positioned at angular intervals ofapproximately 90 degrees. In other embodiments, different numbers andspacing of rotational alignment components can be used. Each rotationalalignment component 2324 can have any of the magnetizationconfigurations described above, including z-pole, quad-pole,triple-pole, or annulus-design configurations, or a differentconfiguration. Further, different rotational alignment components 2324can have different magnetization configurations from each other. Itshould be noted that rotational alignment components 2324 can be placedclose to the perimeter of annular alignment component 2318, and thelarger number of magnetic components can provide sufficient torque witha shorter lever arm. Complementary rotational alignment components canbe disposed around the outer perimeter of any type of annular alignmentcomponent (e.g., primary alignment components, secondary alignmentcomponents, or annular alignment components as described herein).

It will be appreciated that the foregoing examples of rotationalalignment components are illustrative and that variations ormodifications are possible. In some embodiments, a rotational alignmentcomponent can be provided as an optional adjunct to an annular alignmentcomponent, and a device that has both an annular alignment component anda rotational alignment component can align laterally to any other devicethat has a complementary annular alignment component, regardless ofwhether the other device has or does not have a rotational alignmentcomponent. Thus, for example, portable electronic device 1604 of FIG. 16can align rotationally to accessory 1602 (which has both annularalignment component 1616 and rotational alignment component 1622) aswell as aligning laterally to another accessory (such as wirelesscharger device 400 of FIG. 4 ) that has annular alignment component 1616but not rotational alignment component 1622. In the latter case, lateralalignment can be achieved, e.g., to support efficient wireless charging,but there may be no preferred rotational alignment, or rotationalalignment may be achieved using a nonmagnetic feature (e.g., amechanical retention feature such as a ledge, a clip, a notch, or thelike). A rotational magnetic alignment component can be used togetherwith any type of annular magnetic alignment component (e.g., primaryannular magnetic alignment components, secondary annular magneticalignment components, or auxiliary annular magnetic alignment componentsas described below).

3. Primary, Secondary, and Auxiliary Annular Magnetic AlignmentComponents

3.1. Overview of Three-Component Magnetic Alignment Systems

In some embodiments, a magnetic alignment system can align more than twodevices. Examples of magnetic alignment systems with three annularalignment components (referred to as primary, secondary, and auxiliaryannular magnetic alignment components) will now be described. It shouldbe understood that the primary and secondary annular magnetic alignmentcomponents described in this section can be identical to primary andsecondary annular magnetic alignment components described above and thata given pair primary and secondary annular magnetic alignment componentscan be used with or without an auxiliary annular magnetic alignmentcomponent. It should also be understood that a system where alignment isdesired may include more than three devices and that additionalauxiliary annular alignment components can be provided to facilitatealignment of more than three devices.

FIG. 24 shows a simplified representation of a wireless charging system2400 incorporating a three-component magnetic alignment system 2406according to some embodiments. Wireless charging system 2400 includes aportable electronic device 2404, a wireless charger device 2402, and anaccessory 2420 positioned between portable electronic device 2404 andwireless charger device 2402. Portable electronic device 2404 can be aconsumer electronic device, such as a smart phone, tablet, wearabledevice, or the like, or any other electronic device for which wirelesscharging is desired. Wireless charger device 2402 can be any device thatis configured to generate time-varying magnetic flux to induce a currentin a suitably configured receiving device. For instance, wirelesscharger device 2402 can be a wireless charging mat, puck, dockingstation, or the like. Wireless charger device 2402 can include or haveaccess to a power source such as battery power or standard AC power.

To enable wireless power transfer, portable electronic device 2404 andwireless charger device 2402 can include inductive coils 2410 and 2412,respectively, which can operate to transfer power between them. Forexample, inductive coil 2412 can be a transmitter coil that generates atime-varying magnetic flux 2414, and inductive coil 2410 can be areceiver coil in which an electric current is induced in response totime-varying magnetic flux 2414. The received electric current can beused to charge a battery of portable electronic device 2404, to provideoperating power to a component of portable electronic device 2404,and/or for other purposes as desired. In some embodiments, wirelesspower transfer between wireless charger device 2402 and portableelectronic device 2404 can occur regardless of whether accessory 2420 ispresent.

Accessory 2420 can be an accessory that is used with portable electronicdevice 2404 to protect, enhance, and/or supplement the aesthetics and/orfunctions of portable electronic device 2404. For example, accessory2420 can be a protective case, an external battery pack, a cameraattachment, or any other charge-through accessory. In some embodiments,accessory 2420 can include one or more wireless charging coils 2438. Forexample, accessory 2420 can be a portable external battery pack that canbe attached to and carried together with portable electronic device2404. In some embodiments, accessory 2420 can operate wireless chargingcoil 2438 as a receiver coil to charge its onboard battery (e.g., fromwireless charger device 2402) or as a transmitter coil to provide powerto portable electronic device 2404. In some embodiments, accessory 2420cam include separate transmitter and receiver coils 2438. Accessory 2420can operate coil(s) 2438 to transmit power or to receive and store powerdepending on current conditions. In still other embodiments, accessory2420 can be an “unpowered” or “passive” accessory such as a case thatcontains no active circuitry, and wireless charging coil 2438 can beomitted. In such cases, accessory 2420 can be designed not to inhibitwireless power transfer between wireless charger device 2402 andportable electronic device 2404. For instance, relevant portions ofaccessory 2420 can be made of a material such as plastic, leather, orother material that is transparent to time-varying magnetic flux 2414.

To enable efficient wireless power transfer, it is desirable to aligninductive coils 2412 and 2410 (and coil 2438 in embodiments where coil2438 is present). According to some embodiments, magnetic alignmentsystem 2406 can provide such alignment. In the example shown in FIG. 24, magnetic alignment system 2406 includes a primary magnetic alignmentcomponent 2416 disposed within or on a surface of wireless chargerdevice 2402, a secondary magnetic alignment component 2418 disposedwithin or on a surface of portable electronic device 2402, and anauxiliary magnetic alignment component 2470 disposed within or on asurface of accessory 2420. Primary, secondary, and auxiliary magneticalignment components 2416, 2418, and 2470 are configured to magneticallyattract one another into an aligned position in which inductive coils2410 and 2412 (and/or 2438 if present) are aligned with one another toprovide efficient wireless power transfer.

Magnetic alignment system 2406 can enable modularity in that varioustypes of accessories 2420 can align with primary and/or secondarymagnetic alignment components 2416, 2418, provided that accessory 2420includes auxiliary alignment component 2470. For instance, in someembodiments (e.g., where accessory 2420 is a protective case), accessory2420 can mechanically couple to portable electronic device 2404 in afixed position such that auxiliary magnetic alignment component 2470 isaligned with secondary magnetic alignment component 2418, and portableelectronic device 2404 can rely wholly or partially on auxiliarymagnetic alignment component 2470 to align with primary alignmentcomponent 2418 of wireless charger device 2402. Accordingly, whenaccessory 2420 is positioned on charging surface 2408 of wirelesscharger device 2402 such that primary alignment component 2416 isaligned with auxiliary alignment component 2470, secondary alignmentcomponent 2418 of portable electronic device 2404 is also aligned withprimary alignment component 2416, and efficient wireless power transferis supported.

As another example, in some embodiments where accessory 2420 is anexternal battery, auxiliary alignment component 2470 can attract to andalign with secondary alignment component 2418 so that power from aninternal power source (not shown) within accessory 2420 can bewirelessly transferred to portable electronic device 2404 usinginductive coil 2438 and inductive coil 2410. The modularity of magneticalignment system 2406 can also enable wireless charger device 2402 tostack with portable electronic device 2404 and accessory 2420. Forexample, auxiliary alignment component 2470 can attract and align tosecondary alignment component 2418 and at the same time can attract andalign to primary alignment component 2416. Accordingly, when portableelectronic device 2404, accessory 2420, and wireless charger device 2402are all stacked together, power can be transmitted wirelessly fromwireless charger device 2402 to accessory 2420 (e.g., to charge aninternal battery of accessory 2420) and from accessory 2420 to portableelectronic device 2404. Both power transfers can be performedsimultaneously; i.e., wireless charger device 2402 can provide power toaccessory 2420 at the same time that accessory 2420 provides power toportable electronic device 2404. In some embodiments, to enablesimultaneous power transfers, accessory 2420 can include two inductivecoils 2438, one for receiving power and one for transmitting power. Inother embodiments, the power transfers can be performed sequentially;e.g., wireless charger device 2402 can provide power to accessory 2420,and at a time when wireless charger device 2402 is not providing power,accessory 2420 can provide power to portable electronic device 2404.

FIG. 24 is illustrative and not limiting. For example, while FIG. 24shows three devices stacked together, it should be understood that thesame principles can be applied to form systems of four or more devices.For instance, a wireless charging system can include a portableelectronic device coupled to a protective case that is attached to andmagnetically aligned with an external battery, which is attached to andmagnetically aligned to a wireless charger device. All the inductivecoils within the respective devices can be aligned together, andwireless power can be transmitted between the wireless charger deviceand the external battery, between the battery and the portableelectronic device, and/or between the wireless charger device and theportable electronic device. It is to be appreciated that any number ofdevices can be stacked together without departing from the spirit andscope of the present disclosure.

According to embodiments described herein, an alignment component(including a primary, secondary, or auxiliary alignment component) of amagnetic alignment system can be formed of arcuate magnets arranged inan annular configuration. In some embodiments, each magnet can have itsmagnetic polarity oriented in a desired direction so that magneticattraction between the primary, secondary, and auxiliary alignmentcomponents provides a desired alignment. In some embodiments, an arcuatemagnet can include a first magnetic region with magnetic polarityoriented in a first direction and a second magnetic region with magneticpolarity oriented in a second direction different from the firstdirection. As will be described, different configurations can providedifferent degrees of magnetic field leakage.

3.2. Magnetic Alignment Systems with a Single Axial Magnetic Orientation

FIG. 25A shows a perspective view of a magnetic alignment system 2500according to some embodiments, and FIG. 25B shows a cross-sectionthrough magnetic alignment system 2500 across the cut plane indicated inFIG. 25A. Magnetic alignment system 2500 can be an implementation ofmagnetic alignment system 2406 of FIG. 24 . In magnetic alignment system2500, the alignment components all have magnetic polarity oriented inthe same direction (along the axis of the annular configuration).

As shown in FIG. 25A, magnetic alignment system 2500 can include aprimary alignment component 2516 (which can be an implementation ofprimary alignment component 2416 of FIG. 24 ), a secondary alignmentcomponent 2518 (which can be an implementation of secondary alignmentcomponent 2418 of FIG. 24 ), and an auxiliary alignment component 2570(which can be an implementation of auxiliary alignment component 2470described above). Primary alignment component 2516, secondary alignmentcomponent 2518, and auxiliary alignment component 2570 have annularshapes and may also be referred to as “annular” alignment components.The particular dimensions can be chosen as desired. In some embodiments,the dimensions can be similar to example values given above in section1.

Primary alignment component 2516 can include a number of sectors, eachof which can be formed of one or more primary arcuate magnets 2526.Secondary alignment component 2518 can include a number of sectors, eachof which can be formed of one or more secondary arcuate magnets 2528.Auxiliary alignment component 2470 can include a number of sectors, eachof which can be formed of one or more auxiliary arcuate magnets 2572. Inthe example shown, the number of primary magnets 2526 is equal to thenumber of secondary magnets 2528 and to the number of auxiliary magnets2572, and each sector includes exactly one magnet, but this is notrequired. Primary magnets 2526, secondary magnets 2528, and auxiliarymagnets 2572 can have arcuate (or curved) shapes in the transverse planesuch that when primary magnets 2526 (or secondary magnets 2528 orauxiliary magnets 2572) are positioned adjacent to one anotherend-to-end, primary magnets 2526 (or secondary magnets 2528 or auxiliarymagnets 2572) form an annular structure as shown. In some embodiments,primary magnets 2526 can be in contact with each other at interfaces2530, secondary magnets 2528 can be in contact with each other atinterfaces 2532, and auxiliary magnets 2572 can be in contact with eachother at interfaces 2574. Alternatively, small gaps or spaces mayseparate adjacent primary magnets 2526 or adjacent secondary magnets2528 or adjacent auxiliary magnets 2572, providing a greater degree oftolerance during manufacturing.

In some embodiments, primary alignment component 2516 can also includean annular shield 2514 disposed on a distal surface of primary magnets2526. In some embodiments, shield 2514 can be formed as a single annularpiece of material and adhered to primary magnets 2526 to secure primarymagnets 2526 into position. Shield 2514 can be formed of a material thathas high magnetic permeability and/or high magnetic saturation value,such as stainless steel or low-carbon steel, and can redirect magneticfields to prevent them from propagating beyond the distal side ofprimary alignment component 2516, thereby protecting sensitiveelectronic components located beyond the distal side of primaryalignment component 2516 from magnetic interference.

Primary magnets 2526, secondary magnets 2528, and auxiliary magnets 2572can be made of a magnetic material such as an NdFeB material, other rareearth magnetic materials, or other materials that can be magnetized tocreate a persistent magnetic field. Each primary magnet 2526, eachsecondary magnet 2528, and each auxiliary magnet 2572 can have amonolithic structure having a single magnetic region with a magneticpolarity aligned in the axial direction as shown by magnetic polarityindicators 2515, 2517, 2519 in FIG. 25B. For example, each primarymagnet 2526, each secondary magnet 2528, and each auxiliary magnet 2572can be a bar magnet that has been ground and shaped into an arcuatestructure having an axial magnetic orientation. In the example shown,primary magnet 2526 has its north pole oriented toward the proximalsurface and south pole oriented toward the distal surface, secondarymagnet 2528 has its south pole oriented toward the proximal surface andnorth pole oriented toward the distal surface, and auxiliary magnet 2572has a corresponding magnetic orientation such that the north pole ofauxiliary magnet 2572 is oriented toward the proximal surface ofsecondary magnet 2528 and the south pole of auxiliary magnet 2572 isoriented toward the proximal surface of primary magnet 2526. In otherembodiments, the magnetic orientations can be reversed such that primarymagnet 2526 has its south pole oriented toward the proximal surface andnorth pole oriented toward the distal surface while secondary magnet2528 has its north pole oriented toward the proximal surface and southpole oriented toward the distal surface and auxiliary magnet 2572 has acorresponding magnetic orientation such that the south pole of auxiliarymagnet 2572 is oriented toward the proximal surface of secondary magnet2528 and the north pole of auxiliary magnet 2572 is oriented toward theproximal surface of primary magnet 2526.

As shown in FIG. 25B, the axial magnetic orientations of primary magnet2526, auxiliary magnet 2572, and secondary magnet 2528 can generatemagnetic fields 2540 that exert attractive forces between primary magnet2526 and auxiliary magnet 2572 and between auxiliary magnet 2572 andsecondary magnet 2528, thereby facilitating alignment between respectivedevices in which primary alignment component 2516, auxiliary alignmentcomponent 2570, and secondary alignment component 2518 are disposed(e.g., as shown in FIG. 24 ). While shield 2514 can redirect some ofmagnetic fields 2540 away from regions below primary magnet 2526,magnetic fields 2540 may still propagate to regions laterally adjacentto primary magnet 2526 and secondary magnet 2528. In some embodiments,the lateral propagation of magnetic fields 2540 may result in magneticfield leakage to other magnetically sensitive components. For instance,if an inductive coil having a ferromagnetic shield is placed in theinterior (or inboard) region of annular primary alignment component 2516(or secondary alignment component 2518), leakage of magnetic fields 2540may saturate the ferrimagnetic shield, which can degrade wirelesscharging performance.

It will be appreciated that magnetic alignment system 2500 isillustrative and that variations and modifications are possible. Forinstance, while primary alignment component 2516, auxiliary alignmentcomponent 2570, and secondary alignment component 2518 are each shown asbeing constructed of eight arcuate magnets, other embodiments may use adifferent number of magnets, such as sixteen magnets, thirty-sixmagnets, or any other number of magnets, and the number of primarymagnets need not be equal to the number of secondary magnets. Similarly,the number of auxiliary magnets need not be equal to either the numberof primary magnets or the number of secondary magnets. In otherembodiments, primary alignment component 2516 and/or secondary alignmentcomponent 2518 and/or auxiliary alignment component 2570 can each beformed of a single, monolithic annular magnet; however, segmentingalignment components 2516, 2518, and 2570 into arcuate magnets mayimprove manufacturing, as described above with reference to FIGS. 3A and3B.

3.3. Magnetic Alignment Systems with Closed-Loop Magnetic Configurations

As noted above with reference to FIG. 25B, a magnetic alignment systemwith a single axial magnetic orientation may allow lateral leakage ofmagnetic fields, which may adversely affect performance of othercomponents of an electronic device. Accordingly, some embodimentsprovide magnetic alignment systems with a closed-loop magneticconfiguration that reduces magnetic field leakage. Examples will now bedescribed.

FIG. 26A shows a perspective view of a magnetic alignment system 2600according to some embodiments, and FIG. 26B shows a cross-sectionthrough magnetic alignment system 2600 across the cut plane indicated inFIG. 26A. Magnetic alignment system 2600 can be an implementation ofmagnetic alignment system 2406 of FIG. 24 . In magnetic alignment system2600, the alignment components have magnetic components configured in a“closed loop” configuration as described below.

As shown in FIG. 26A, magnetic alignment system 2600 can include aprimary alignment component 2616 (which can be an implementation ofprimary alignment component 2416 of FIG. 24 ), a secondary alignmentcomponent 2618 (which can be an implementation of secondary alignmentcomponent 2418 of FIG. 24 ), and an auxiliary alignment component 2670(which can be an implementation of auxiliary alignment component 2470 ofFIG. 24 ). Primary alignment component 2616, secondary alignmentcomponent 2618, and auxiliary alignment component 2670 have annularshapes and may also be referred to as “annular” alignment components.The particular dimensions can be chosen as desired. In some embodiments,the dimensions can be similar to example values given above in section1.

Primary alignment component 2616 can include a number of sectors, eachof which can be formed of a number of primary magnets 2626; secondaryalignment component 2618 can include a number of sectors, each of whichcan be formed of a number of secondary magnets 2628; and auxiliaryalignment component 2670 can include a number of sectors, each of whichcan be formed of a number of auxiliary magnets 2672. In the exampleshown, the number of primary magnets 2626 is equal to the number ofsecondary magnets 2628 and to the number of auxiliary magnets 2672, andeach sector includes one magnet, but this is not required. Primarymagnets 2626, secondary magnets 2628, and auxiliary magnets 2672 canhave arcuate (or curved) shapes in the transverse plane such that whenprimary magnets 2626 (or secondary magnets 2628 or auxiliary magnets2672) are positioned adjacent to one another end-to-end, primary magnets2626 (or secondary magnets 2628 or auxiliary magnets 2672) form anannular structure as shown. In some embodiments, adjacent primarymagnets 2626 can be in contact with each other at interfaces 2630,adjacent secondary magnets 2628 can be in contact with each other atinterfaces 2632, and adjacent auxiliary magnets 2672 can be in contactwith each other at interfaces 2680. Alternatively, small gaps or spacesmay separate adjacent primary magnets 2626, adjacent secondary magnets2628, or adjacent auxiliary magnets 2672, providing a greater degree oftolerance during manufacturing.

In some embodiments, primary alignment component 2616 can also includean annular shield 2614 disposed on a distal surface of primary magnets2626. In some embodiments, shield 2614 can be formed as a single annularpiece of material and adhered to primary magnets 2626 to secure primarymagnets 2626 into position. Shield 2614 can be formed of a material thathas high magnetic permeability, such as stainless steel, and canredirect magnetic fields to prevent them from propagating beyond thedistal side of primary alignment component 2616, thereby protectingsensitive electronic components located beyond the distal side ofprimary alignment component 2616 from magnetic interference. In someembodiments, auxiliary alignment component 2670 does not include asimilar shield, so that a stronger magnetic attraction with primaryalignment component 2616 can be provided.

Primary magnets 2626, secondary magnets 2628, and auxiliary magnets 2672can be made of a magnetic material such as an NdFeB material, other rareearth magnetic materials, or other materials that can be magnetized tocreate a persistent magnetic field. Each secondary magnet 2628 can havea single magnetic region with a magnetic polarity having a component inthe radial direction in the transverse plane (as shown by magneticpolarity indicator 2617 in FIG. 26B). As described below, the magneticorientation can be in a radial direction with respect to axis 2601 oranother direction having a radial component in the transverse plane.Each primary magnet 2626 can include two magnetic regions havingopposite magnetic orientations. For example, each primary magnet 2626can include an inner arcuate magnetic region 2652 having a magneticorientation in a first axial direction (as shown by polarity indicator2653 in FIG. 26B), an outer arcuate magnetic region 2654 having amagnetic orientation in a second axial direction opposite the firstdirection (as shown by polarity indicator 2655 in FIG. 26B), and acentral non-magnetized region 2656 that does not have a magneticorientation. Central non-magnetized region 2656 can magneticallyseparate inner arcuate region 2652 from outer arcuate region 2654 byinhibiting magnetic fields from directly crossing through center region2656. Similarly, each auxiliary magnet 2672 can include two magneticregions having opposite magnetic orientations. For example, eachauxiliary magnet 2672 can include an inner arcuate magnetic region 2674having a magnetic orientation in a first axial direction (as shown bypolarity indicator 2673 in FIG. 26B), an outer arcuate magnetic region2676 having a magnetic orientation in a second axial direction oppositethe first direction (as shown by polarity indicator 2675 in FIG. 26B),and a central non-magnetized region 2678 that does not have a magneticorientation. Central non-magnetized region 2678 can magneticallyseparate inner arcuate region 2674 from outer arcuate region 2676 byinhibiting magnetic fields from directly crossing through center region2678.

In some embodiments, each secondary magnet 2626 can be made of amagnetic material that has been ground and shaped into an arcuatestructure, and a magnetic orientation having a radial component in thetransverse plane can be created, e.g., using a magnetizer. Similarly,each primary magnet 2626 can be made of a single piece of magneticmaterial that has been ground and shaped into an arcuate structure, anda magnetizer can be applied to the arcuate structure to induce an axialmagnetic orientation in one direction within an inner arcuate region ofthe structure and an axial magnetic orientation in the oppositedirection within an outer arcuate region of the structure, whiledemagnetizing or avoiding creation of a magnetic orientation in thecentral region. In some alternative embodiments, each primary magnet2626 can be a compound structure with two arcuate pieces of magneticmaterial providing inner arcuate magnetic region 2652 and outer arcuatemagnetic region 2654; in such embodiments, central non-magnetized region2656 can be formed of an arcuate piece of nonmagnetic material or formedas an air gap defined by sidewalls of inner arcuate magnetic region 2652and outer arcuate magnetic region 2654. Any manufacturing technique thatcan be used to form primary magnets 2626 can also be used to formauxiliary magnets 2672. Thus, each auxiliary magnet 2672 can be made ofa single piece of magnetic material that has been ground and shaped intoan arcuate structure, and a magnetizer can be applied to the arcuatestructure to induce an axial magnetic orientation in one directionwithin an inner arcuate region of the structure and an axial magneticorientation in the opposite direction within an outer arcuate region ofthe structure, while demagnetizing or avoiding creation of a magneticorientation in the central region. In some alternative embodiments, eachauxiliary magnet 2672 can be a compound structure with two arcuatepieces of magnetic material providing inner arcuate magnetic region 2674and outer arcuate magnetic region 2676; in such embodiments, centralnon-magnetized region 2678 can be formed of an arcuate piece ofnonmagnetic (or demagnetized) material or formed as an air gap definedby sidewalls of inner arcuate magnetic region 2674 and outer arcuatemagnetic region 2676. It should be understood that in some embodimentsone manufacturing technique can be used for primary magnets 2626 while adifferent manufacturing technique can be used for auxiliary magnets2672; for example, each auxiliary magnet 2672 can be monolithic whileeach primary magnet 2626 is a compound structure. As long as themagnetic fields of the various magnets align as described, alignmentbetween devices can be provided. Further, as described above withreference to FIGS. 3A and 3B, the inner and outer arcuate magneticregions of a quad-pole primary or auxiliary arcuate magnet can but neednot have equal magnetic field strength; asymmetric polarization asdescribed above can be applied.

As shown in FIG. 26B, inner arcuate magnetic region 2652 of primarymagnet 2626 and inner arcuate magnetic region 2674 of auxiliary magnet2672 can have the same magnetic orientation, as shown by polarityindictors 2653 and 2673. Similarly, outer arcuate magnetic region 2654of primary magnet 2626 and outer arcuate magnetic region 2676 ofauxiliary magnet 2672 can have the same magnetic orientation, as shownby polarity indictors 2655 and 2675. This configuration creates amagnetic attraction between primary magnet 2626 and auxiliary magnet2672, which can facilitate alignment between them. The magnetic polarityof secondary magnet 2628 (shown by indicator 2617) can be oriented suchthat when secondary magnetic alignment component 2618 is aligned withauxiliary magnetic alignment component 2670, the south pole of secondarymagnet 2628 is oriented toward the north pole of inner arcuate magneticregion 2674 of auxiliary magnet 2672 (and also toward the north pole ofinner arcuate magnetic region 2652 of primary magnet 2626) while thenorth pole of secondary magnet 2628 is oriented toward the south pole ofouter arcuate magnetic region 2676 of auxiliary magnet 2672 (and alsotoward the south pole of outer arcuate magnetic region 2654 of primarymagnet 2626).

Accordingly, the respective magnetic orientations of inner arcuatemagnetic regions 2652, 2674, secondary magnet 2628 and outer arcuatemagnetic region 2676, 2678 can generate magnetic fields 2640 that exertan attractive force between primary magnet 2626 and auxiliary magnet2672 and between auxiliary magnet 2672 and secondary magnet 2628,thereby facilitating alignment between respective electronic devices inwhich primary alignment component 2616, auxiliary alignment component2670, and secondary alignment component 2618 are disposed (e.g., asshown in FIG. 24 ). Shield 2614 at the distal surface of primary magnet2626 can redirect some of magnetic fields 2640 away from regions belowprimary magnet 2626. Further, the “closed-loop” magnetic field 2640formed around central non-magnetized regions 2656 and 2678 can havetight and compact field lines that do not stray outside of primary,auxiliary, and secondary magnets 2626, 2672, 2628 as far as magneticfield 2540 strays outside of primary, auxiliary, and secondary magnets2526, 2572, 2528 in FIG. 25B. Thus, magnetically sensitive componentscan be placed relatively close to primary alignment component 2616 withreduced concern for stray magnetic fields. Accordingly, as compared tomagnetic alignment system 2500, magnetic alignment system 2600 can helpto reduce the overall size of a device in which primary alignmentcomponent 2616 is positioned and can also help reduce noise created bymagnetic field 2640 in adjacent components, such as an inductivereceiving coil positioned inboard of secondary alignment component 2618.

It will be appreciated that magnetic alignment system 2600 isillustrative and that variations and modifications are possible. Forinstance, while primary alignment component 2616, auxiliary alignmentcomponent 2672, and secondary alignment component 2618 are each shown asbeing constructed of eight arcuate magnets, other embodiments may use adifferent number of magnets, such as sixteen magnets, thirty-sixmagnets, or any other number of magnets, and the number of primarymagnets need not be equal to the number of secondary magnets. Similarly,the number of auxiliary magnets need not be equal to either the numberof primary magnets or the number of secondary magnets. In otherembodiments, secondary alignment component 2618 can be formed of asingle, monolithic annular magnet. Similarly, primary alignmentcomponent 2616 and/or auxiliary alignment component 2672 can each beformed of a single, monolithic annular piece of magnetic material withan appropriate magnetization pattern as described above, or primaryalignment component 2616 and/or auxiliary alignment component 2672 caneach be formed of a monolithic inner annular magnet and a monolithicouter annular magnet, with an annular air gap or region of nonmagneticmaterial disposed between the inner annular magnet and outer annularmagnet. However, a construction using multiple arcuate magnets mayimprove manufacturing because smaller arcuate magnets are less brittlethan a single, monolithic annular magnet and are less prone to yieldloss due to physical stresses imposed on the magnetic material duringmanufacturing. It should also be understood that the magneticorientations of the various components or individual magnets do not needto align exactly with the lateral and axial directions. The magneticorientation can have any angle that provides a closed-loop path for amagnetic field through the primary and secondary alignment components.

3.4. Magnetic Orientation for a Closed-Loop Magnetic Alignment System

Any of the magnetic orientations described above with reference to FIG.4, 5, 7, 8A-8C, 9A-9B, or 10 can also be applied to systems that includean auxiliary alignment component. The magnetic orientation of theauxiliary magnets can be made to match that of corresponding primarymagnets.

3.5. Annular Magnetic Alignment Components with Gaps

In examples described above, the primary magnetic alignment component,secondary magnetic alignment component, and auxiliary magnetic alignmentcomponent have annular shapes. As described above (e.g., with referenceto FIG. 3A), the annulus can be completely closed. In other embodiments,the annulus can include one or more gaps, where each gap can be asection of an annulus where magnetic material (or any material) isabsent. An example magnetic alignment component with a gap is describedabove with reference to FIG. 11 , and it should be understood that anauxiliary alignment component can also include one or more gaps, e.g.,to accommodate a form factor of an accessory device in which anauxiliary magnetic alignment component is present and/or to accommodateelectronic circuit components that may be present in the accessorydevice. Further, compatible annular alignment components in differentdevices can differ as to the number, size, and/or position of gaps.

3.6. Accessory Devices Incorporating Magnetic Alignment Components

FIG. 27 shows a simplified rear view of an accessory device 2700incorporating an auxiliary magnetic alignment component according tosome embodiments. In the example shown, the accessory deviceincorporates an auxiliary alignment component; however, it should beunderstood that an accessory device can instead incorporate a primary orsecondary magnetic alignment component.

Accessory device 2700 can be, for example, a protective or esthetic casefor a portable electronic device such as smart phone 1200 of FIG. 12A.Accordingly, accessory device 2700 can have a housing 2702, which can bethe same size as (or slightly larger than) smart phone 1200. In someembodiments, housing 2702 can be shaped as a tray that covers the sideand rear surfaces of smart phone 1200, leaving the front (display)surface of smart phone 1200 exposed. Housing 2702 (or portions thereof)can be made of plastic, rubber, silicone, leather, and/or othermaterials. An auxiliary alignment component 2770 can be disposed withinhousing 2702, in a position such that, when smart phone 1200 is insertedinto accessory device 2700 in the preferred orientation, auxiliaryalignment component 2770 is coaxially aligned with secondary alignmentcomponent 1218 of smart phone 1200.

Auxiliary alignment component 2770 can be, for example, animplementation of any of the auxiliary alignment components describedabove and can include an annular arrangement of magnets 2772 withinterfaces 2780, which can be air gaps or interfaces where adjacentmagnets contact one another. Magnets 2772 can have a quad-poleconfiguration as described above; for instance, each magnet 2772 caninclude an inner arcuate region having an axial magnetic orientation ina first direction, an outer arcuate region having an axial magneticorientation in a second direction opposite the first direction, and acentral arcuate region having no distinct magnetic orientation. Althoughnot shown in FIG. 27 , auxiliary magnetic alignment component 2770 caninclude one or more gaps between adjacent magnets 2772. In someembodiments, the gap(s) can provide electrical connection paths forwires (or conductive traces) to connect between regions inboard of andoutboard of auxiliary magnetic alignment component 2770, and in someembodiments, the gap(s) can be arranged to allow housing 2702 to have areduced lateral size for use with a smart phone having a smaller formfactor. For instance, the pattern of gaps can match that of magneticalignment component 1218′ of smart phone 1200′ of FIG. 12B.

In the example shown, accessory device 2700 is a passive device whosefunction may be protective and/or esthetic. As such, it may be desirableto make accessory device 2700 thin and to provide smooth inner and outersurfaces. In some embodiments, magnets 2772 can have a thin axialdimension so that accessory device 2700 can have smooth surfaces and adesired thinness. Accessory device 2700 can have a variety of shapes andfeatures. For example, accessory device 2700 can be a tray that coversthe side and rear surfaces of smart phone 1200, leaving the front(display) surface of smart phone 1200 exposed. Alternatively, accessorydevice 2700 can include a cover that can be folded over the frontsurface of smart phone 1200 and unfolded to allow access to the display.As another example, accessory device 2700 can be formed as a sleevehaving an opening at one end (e.g., the top end or a side) to allowsmart phone 1200 to be inserted into the sleeve when not in use andremoved from the sleeve for use.

In the example shown, accessory device 2700 can a passive device thatdoes not contain power-consuming components. Accordingly, the region2711 inboard of annular alignment component 2770 can be made of the samematerial as the surrounding housing 2702, providing a continuous backsurface for accessory device 2700. Alternatively, part or all of region2711 may be devoid of material, allowing the corresponding portion ofthe rear surface of smart phone 1200 to be exposed. In some embodiments,housing 2702 of accessory device 2700 (or portions thereof) can be madeof transparent material so that the rear surface of smart phone 1200 (orportions thereof) can be seen through accessory device 2700. In theabsence of transparent magnetic material, an annular region of opaquematerial can be disposed over magnetic alignment component 2770 so thatthe individual magnets are not visible. The opaque material can have acolor (or colors) selected for a desired esthetic effect.

In some embodiments, accessory 2700 can be an active device. Forexample, accessory 2700 can include an external battery that can providepower to smart phone 1200. Accordingly, central region 2711 can includeone or more wireless charging coils, which can be arranged and operatedas described above with reference to accessory 2420 of FIG. 24 .

3.7. Wireless Charging Systems with Magnetic Alignment

FIG. 28A shows a simplified perspective view of a system 2800 includingportable electronic device 1200 (of FIG. 12A) in alignment withaccessory device 2700 (of FIG. 27 ) and wireless charger device 1300 (ofFIG. 13 ) according to some embodiments. In FIG. 28A, portions ofwireless charger device 1300 and accessory device 2700 are shown usingdashed lines to avoid obscuring other details. As shown, accessorydevice 2700 can be placed adjacent to portable electronic device 1200,for example by inserting portable electronic device 1200 into accessorydevice 2700, and wireless charger device 1300 can be placed with itscharging (or proximal) surface against the rear (or proximal) surface2803 of accessory device 2700. When the devices are placed in thisarrangement, secondary alignment component 1218 in portable electronicdevice 1200 is aligned with auxiliary alignment component 2770 ofaccessory device 2700 and with primary alignment component 1316 ofwireless charger device 1300. Accordingly, auxiliary alignment component2770 in accessory device 2700 and secondary alignment component 1218 inportable electronic device 120 can attract and hold primary magneticalignment component 1316 of wireless charger device 1300 in alignment sothat transmitter coil assembly 1312 of wireless charger device 1300 isaligned with coil assembly 1210 of portable electronic device 1200. Asshown, wireless charger device 1300 can have any rotational orientationabout an axis defined by the centers of primary magnetic alignmentcomponent 1316 and secondary magnetic alignment component 1218; forinstance, gap 1201 in secondary magnetic alignment component 1218 neednot align with gap 1301 in primary magnetic alignment component 1316.

FIG. 28B shows a simplified partial cross section view of system 2800according to some embodiments. Portable electronic device 1200 has arear housing 2802 (which can be made of a material such as glass orplastic that is permeable to electromagnetic fields and to DC magneticfields) and a front housing 2804 (which can include a touch screendisplay). Coil assembly 1210 can include an inductive receiver coil 2810(which can be made, e.g., of stranded wire wound into a coil) andshielding 2812 (which can include, e.g., a ferrimagnetic shield).Secondary magnet 2828 forms a portion of secondary magnetic alignmentcomponent 1218 and can have a magnetic field oriented in a radiallyinward direction (as shown by the arrow). It should be understood thatalthough secondary alignment component 1218 is shown in FIG. 28A, rearhousing 2802 can be opaque and secondary alignment component 1218 neednot be visible to a user.

Wireless charger device 1300 has a housing 1302 that includes asingle-piece enclosure 2806 forming distal and side surfaces of housing1302 and a top cap 2808 forming a proximal surface of housing 1302. Asdescribed above, enclosure 2806 and top cap 2808 can be made of the samematerial or different materials, and top cap 2808 can be made of amaterial that is permeable to AC electromagnetic fields and to DCmagnetic fields. Transmitter coil assembly 1312 can include an inductivetransmitter coil 2816 (which can be made, e.g., of stranded wire woundinto a coil) and electromagnetic shielding 2814 (which can include,e.g., a ferrimagnetic shield). Primary arcuate magnet 2826 forms aportion of primary magnetic alignment component 1316 and can include aninner arcuate region 2852 having a magnetic field oriented in a firstaxial direction, an outer arcuate region 2854 having a magnetic fieldoriented in a second axial direction opposite the first axial direction,and a non-magnetized central arcuate region 2856. As described above, ashield 2814 can be disposed on the distal surface of primary magnet2826. It should be understood that although primary alignment component1316 is shown in FIG. 28A, housing 1302 can be opaque and primaryalignment component 1316 need not be visible to a user.

Accessory device 2700 has a rear housing 2702 that includes a back layer2805 (forming back surface 2803) and a front layer 2807 that contactsrear housing 2802 of portable electronic device 1200 at a surface 2809.Back layer 2805 and front layer 2807 can be made of the same material ordifferent materials as desired. Auxiliary arcuate magnet 2872 forms aportion of auxiliary alignment component 2770 and can include an innerarcuate section 2874 having a magnetic field oriented in a first axialdirection, an outer arcuate section 2876 having a magnetic fieldoriented in a second axial direction opposite the first axial direction,and a non-magnetized central arcuate section 2878. It should beunderstood that although auxiliary alignment component 2770 is shown inFIG. 28A, rear housing 2702 can be opaque and auxiliary alignmentcomponent 2770 need not be visible to a user.

When aligned, primary magnet 2826, auxiliary magnet 2872, and secondarymagnet 2828 produce a closed-loop magnetic flux as shown by lines 2840.Magnetic flux 2840 can attract primary annular alignment component 1318,auxiliary annular alignment component 2770 and secondary annularalignment component 1216 into alignment such that the respective centersof primary annular alignment component 1318, auxiliary annular alignmentcomponent 2770, and secondary annular alignment component 1216 arealigned along a common axis. Since transmitter coil 2816 is fixed in aposition concentric with primary alignment component 1316 and receivercoil 2810 is fixed in position concentric with secondary alignmentcomponent 1218, a result of aligning primary annular alignment component1318, auxiliary annular alignment component 2770, and secondary annularalignment component 1216 along a common axis is that transmitter coil2816 and receiver coil 2810 are also aligned along a common axis,thereby enabling efficient wireless power transfer. For instance,transmitter coil 2816 can be driven with an alternating current togenerate time-varying magnetic fields that induce a time-varying currentin receiver coil 2816. Electromagnetic shielding (e.g., shielding 2814and 2812) can confine the AC fields to the immediate vicinity of coils2816 and 2812. Further, in embodiments where accessory device 2700includes one or more wireless charging coils, such wireless chargingcoils can also be aligned along a common axis with coils 2816 and 2810.

Some embodiments provide a gap region 2811 between secondary magnet 2828and coil assembly 1210 that may experience low DC magnetic flux and mayalso experience low AC electromagnetic fields due to electromagneticshielding 2812 around coil 2810. Similarly, some embodiments provide agap region 2813 between primary magnet 2826 and transmitter coilassembly 1312 that may experience low DC magnetic flux and may alsoexperience low AC electromagnetic fields due to electromagneticshielding 2818 around transmitter coil 2816.

As can be appreciated with reference to FIG. 28B, arcuate magnets 2828of secondary alignment component 1218 can have a thin axial dimension sothat secondary alignment component 1218 does not require an increasedthickness of portable electronic device 1200. For instance, the axialthickness of each secondary alignment magnet 2828 can be less than orequal to the thickness of receiver coil assembly 1210 (including coil2810 and shielding 2812). Primary alignment magnets 2826 can have athicker axial dimension, e.g., occupying all of the axial space betweenenclosure 2806 and top cover 2808.

Similarly, each arcuate magnet 2872 of auxiliary alignment component2770 can have a thin axial dimension so that the overall thickness ofaccessory device 2700 can be kept small. Back layer 2805 and front layer2807 can be planar layers. Space between layers 2805 and 2807 that isnot occupied by auxiliary alignment magnets 2872 can be an air gap, orportions or all of the space may be filled with material. In someembodiments, surfaces 2803 and 2809 do not evince a local deviation fromflatness due to the presence of auxiliary alignment magnets 2872. Insome embodiments, accessory device 2700 (or a back housing elementthereof) can be formed as a single piece of material with auxiliaryalignment component 2770 embedded therein. Auxiliary alignment magnets2872 and primary alignment magnets 2826 can have the same radial width;in some embodiments, the radial width of auxiliary alignment magnets2872 and primary alignment magnets 2826 can be slightly larger than theradial width of secondary alignment magnets 2828.

It should be understood that auxiliary alignment component 2770 isoptional, and a charge-through accessory that does not have an auxiliaryalignment component may be positioned between portable electronic device1200 and wireless charger device 1300. Depending on the thickness andmaterial composition of the accessory, primary annular alignmentcomponent 1316 and secondary annular alignment component 1218 may stillexperience sufficient attraction to provide reliable alignment betweencoils 2816 and 2810. However, for DC magnets, the attractive forcediminishes sharply with increasing distance between magnets, so thealignment may be less strong. Accordingly, auxiliary alignment component2770 can be used as a “repeater” that decreases the distance betweenadjacent magnets and thus increases the magnetic force that urges towardalignment.

FIG. 29 is a block diagram illustrating an exemplary wireless chargingsystem 2900 including a portable electronic device 2904 (which can be,e.g., portable electronic device 1200 or any other portable electronicdevice described herein), a wireless charger device 2902 (which can be,e.g., wireless charger device 1300 or any other wireless charger devicedescribed herein), and an accessory device 2906 (which can be, e.g.,accessory device 2800 or any other accessory device described herein)that can be aligned together via a magnetic alignment system 2908according to some embodiments. Magnetic alignment system 2908 caninclude a primary alignment component 2916 within wireless chargerdevice 2902, a secondary alignment component 2918 within portableelectronic device 2904, and an auxiliary alignment component 2970 withinaccessory device 2906. Primary alignment component 2916, secondaryalignment component 2918, and auxiliary alignment component 2970 can beconstructed according to any of the embodiments described herein.Portable electronic device 2904 can include a computing system 2941coupled to a memory bank 2942. Computing system 2941 can include controlcircuitry configured to execute instructions stored in memory bank 2942for performing various functions for operating portable electronicdevice 2904. The control circuitry can include one or more programmableintegrated logic circuits, such as microprocessors, central processingunits (CPUs), graphics processing units (GPUs), field programmable gatearrays (FPGAs), or the like.

Computing system 2941 can also be coupled to a user interface system2943, a communication system 2944, and a sensor system 2945 for enablingportable electronic device 2904 to perform one or more functions. Forinstance, user interface system 2943 can include a display, speaker,microphone, actuator for enabling haptic feedback, and one or more inputdevices such as a button, switch, capacitive screen for enabling thedisplay to be touch sensitive, and the like. Communication system 2944can include wireless telecommunication components, NFC components,Bluetooth components, and/or Wi-Fi components for enabling portableelectronic device 2904 to make phone calls, interact with wirelessaccessories, and access the Internet. Sensor system 2945 can includelight sensors, accelerometers, gyroscopes, temperature sensors,magnetometers, and/or any other type of sensor that can measure aparameter of an external entity and/or environment.

All of these electrical components require a power source to operate.Accordingly, portable electronic device 2904 also includes a battery2946 that can discharge stored energy to power the electrical componentsof portable electronic device 2904. To replenish the energy dischargedto power the electrical components, portable electronic device 2904includes charging circuitry 2947 and an inductive coil 2910 that canreceive power from wireless charger device 2902 coupled to an externalpower source 2922.

Wireless charger device 2902 can include a transmitter coil 2912 forgenerating time-varying magnetic flux capable of inducing an electricalcurrent in coil 2910 of portable electronic device 2904. The inducedcurrent can be used by charging circuitry 2947 to charge battery 2946.Wireless charger device 2902 can further include a computing system 2921coupled to a communication system 2922 and wireless charging circuitry2923. Wireless charging circuitry can include circuit components toconvert standard AC power having a first set of voltage and frequencycharacteristics (e.g., standard AC wall power) to AC power suitable foroperating coil 2910. Suitable circuit components, including rectifiers(AC-to-DC converters), boost circuits (DC-to-DC voltage boostingcircuits), inverters (DC-to-AC converters), and the like, are known inthe art. Computing system 2921 can include logic circuitry (such as amicroprocessor, microcontroller, FPGA, or the like) configured tocontrol the operation of wireless charger device 2902, such as tocontrol wireless charging circuitry 2923 to use power received fromexternal power source 2922 to generate time-varying magnetic flux toinduce current in coil 2910 to charge portable electronic device 2904.In some embodiments, computing system 2921 can implement functionalityconfirming to the Qi standard for wireless charging (promulgated by theWireless Power Consortium).

In some embodiments, components implementing computing system 2921 andwireless charging circuitry 2923 can be disposed within the housing thatholds coil 2912 and primary alignment component 2916 (e.g., withinpuck-shaped housing 1302 of FIGS. 13 and 14A-14B). In other embodiments,some or all of the components implementing computing system 2921 andwireless charging circuitry 2923 can be disposed elsewhere, e.g., at thedistal end of cable 1304 in FIGS. 13 and 14A. For example, the logiccircuitry implementing computing system 2921 can be disposed withinhousing 1302 while wireless charging circuitry 2932 is disposed in aboot of a plug connector at the distal end of cable 1304. (In this case,cable 1304 can provide AC power to wireless charger device 1300.) Asanother example, the logic circuitry implementing computing system 2921and circuit components implementing portions of wireless chargingcircuitry 2923 can be disposed within housing 1302 while circuitcomponents implementing other portions of wireless charging circuitry2923 are disposed in a boot of a plug connector at the distal end ofcable 1304. For instance, an inverter may be disposed within housing1302 while a rectifier and boost circuit are disposed in the boot. (Inthis case, cable 1304 can provide DC power to wireless charger device1300.)

As described above, accessory device 2906 can be a passive accessorysuch as protective case for portable electronic device 1002 and need notinclude any components other than auxiliary alignment component 2970. Insome embodiments, accessory device 2906 can be an active device. Forinstance, accessory device 2906 can include a computing system 2961coupled to a memory bank 2962 and a communication system 2963. Computingsystem 2961 can execute instructions stored in memory bank 2962 toperform one or more functions using communication system 2963. In someembodiments, computing system 2961 can be configured to send data frommemory bank 2962 through communication system 2963 to portableelectronic device 2904 regarding a user interface theme for portableelectronic device 2904 so that portable electronic device 2904 can usethis data to modify its user interface. As an example, accessory device2906 can be a protective case that has a picture of a car on it, andmemory bank 2962 has information stored for configuring a user interfaceto include a car theme with car-related icons, animations, and/orsounds. Thus, when accessory device 2906 is installed on portableelectronic device 2902, computing system 2941 can receive the car-themeduser interface from accessory device 2906 and can modify user interfacesystem 2943 according to the received car-themed data (e.g., changingwhat is displayed, what sounds are played to signal events, etc.). Insome embodiments, accessory device 2906 can also include a wirelesscharging component 2964 that can aid in wireless charging betweenportable electronic device 2904 and wireless charger device 2902. Forinstance, wireless charging component 2964 can include a block ofmagnetic material that can help guide magnetic flux through accessorydevice 2906. Or, wireless charging component 2964 can include a pair ofinductor coils where one inductor coil positioned proximate to wirelesscharger device 2902 can receive magnetic flux, which can be relayed tothe other inductor coil positioned proximate to portable electronicdevice 2904 so that the received flux can be retransmitted to portableelectronic device 2904. In some embodiments, accessory device 2906 caninclude a battery (not shown) to store power received from wirelesscharger device 2902 at a first time for delivery to portable electronicdevice 2904 at a later time.

While system 2900 is described with reference to particular blocks, itis to be understood that these blocks are defined for convenience ofdescription and are not intended to imply a particular physicalarrangement of component parts. The blocks need not correspond tophysically distinct components, and the same physical components can beused to implement aspects of multiple blocks. Blocks can be configuredto perform various operations, e.g., by programming a processor orproviding appropriate control circuitry, and various blocks might ormight not be reconfigurable depending on how the initial configurationis obtained. Embodiments of the present invention can be realized in avariety of apparatus including electronic devices that use using anycombination of circuitry and software to enable wireless chargingoperations and/or other operations where physical alignment betweendevices is desired.

4. Systems with Movable Magnetic Alignment Components

In embodiments described above, it is assumed (though not required) thatthe magnetic alignment components (including annular magnetic alignmentcomponents, and, where applicable, rotational magnetic alignmentcomponents) are fixed in position relative to the device housing (orenclosure) and do not move in the axial or lateral direction. Thisprovides a fixed magnetic flux. In some embodiments, it may be desirablefor one or more of the magnetic alignment components to move in theaxial direction. For example, in various embodiments of the presentinvention, it can be desirable to limit the magnetic flux provided bythese magnetic structures. Limiting the magnetic flux can help toprevent the demagnetization of various charge and payment cards that auser might be carrying with an electronic device that incorporates oneof these magnetic structures. But in some circumstances, it can bedesirable to increase this magnetic flux in order to increase a magneticattraction between an electronic device and an accessory or a secondelectronic device. Also, it can be desirable for one or more of themagnetic alignment components to move laterally. For example, anelectronic device and an attachment structure or wireless device can beoffset from each other in a lateral direction. The ability of a magneticalignment component to move laterally can compensate for this offset andimprove coupling between devices, particularly where a coil moves withthe magnetic alignment component. Accordingly, embodiments of thepresent invention can provide structures where some or all of themagnets in these magnetic structures are able to change positions orotherwise move. Examples of magnetic structures having moving magnetsare shown in the following figures.

FIGS. 30A-30C illustrate examples of moving magnets according to anembodiment of the present invention. In this example, first electronicdevice 3000 can be a wireless charger device or other device having amagnet 3010 (which can be, e.g., any of the annular or rotationalmagnetic alignment components described herein). In FIG. 30A, movingmagnet 3010 can be housed in a first electronic device 3000. Firstelectronic device 3000 can include device enclosure 3030, magnet 3010,and shield 3020. Magnet 3010 can be in a first position (not shown)adjacent to nonmoving shield 3020. In this position, magnet 3010 can beseparated from device enclosure 3030. As a result, the magnetic flux3012 at a surface of device enclosure 3030 can be relatively low,thereby protecting magnetic devices and magnetically stored information,such as information stored on payment cards. As magnet 3010 in firstelectronic device 3000 is attracted to a second magnet (not shown) in asecond electronic device (not shown), magnet 3010 can move, for exampleit can move away from shield 3020 to be adjacent to device enclosure3030, as shown. With magnet 3010 at this location, magnetic flux 3012 atsurface of device enclosure 3030 can be relatively high. This increasein magnetic flux 3012 can help to attract the second electronic deviceto first electronic device 3000.

With this configuration, it can take a large amount of magneticattraction for magnet 3010 to separate from shield 3020. Accordingly,these and other embodiments of the present invention can include ashield that is split into a shield portion and a return plate portion.For example, in FIG. 30B, line 3060 can be used to indicate a split ofshield 3020 into a shield 3040 and return plate 3050.

In FIG. 30C, moving magnet 3010 can be housed in first electronic device3000. First electronic device 3000 can include device enclosure 3030,magnet 3010, shield 3040, and return plate 3050. In the absence of amagnetic attraction, magnet 3010 can be in a first position (not shown)such that shield 3040 can be adjacent to return plate 3050. Again, thisconfiguration, magnetic flux 3012 at a surface of device enclosure 3030can be relatively low. As magnet 3010 and first electronic device isattracted to a second magnet (not shown) in a second electronic device(not shown), magnet 3010 can move, for example it can move away fromreturn plate 3050 to be adjacent to device enclosure 3030, as shown. Inthis configuration, shield 3040 can be separate from return plate 3050and the magnetic flux 3012 at a surface of device enclosure 3030 can beincreased. As before, this increase in magnetic flux 3012 can help toattract the second electronic device to the first electronic device3000.

In these and other embodiments of the present invention, varioushousings and structures can be used to guide a moving magnet. Also,various surfaces can be used in conjunction with these moving magnets.These surfaces can be rigid. Alternatively, these surfaces can becompliant and at least somewhat flexible. Examples are shown in thefollowing figures.

FIGS. 31A and 31B illustrate a moving magnetic structure according to anembodiment of the present invention. In this example, first electronicdevice 3100 can be a wireless charger device or other device having afirst magnet 3110 (which can be, e.g., any of the annular or rotationalmagnetic alignment components described herein). FIG. 31A illustrates amoving first magnet 3110 in a first electronic device 3100. Firstelectronic device 3100 can include first magnet 3110, protective surface3112, housings 3120 and 3122, compliant structure 3124, shield 3140, andreturn plate 3150. In this figure, first magnet 3110 is not attracted toa second magnet (not shown), and therefore shield 3140 is magneticallyattracted to or attached to return plate 3150. In this position,compliant structure 3124 can be expanded or relaxed. Compliant structure3124 can be formed of an elastomer, silicon rubber open cell foam,silicon rubber, polyurethane foam, or other foam or other compressiblematerial.

In FIG. 31B, second electronic device 3160 has been brought intoproximity of first electronic device 3100. Second magnet 3170 canattract first magnet 3110, thereby causing shield 3140 and return plate3150 to separate. Housings 3120 and 3122 can compress compliantstructure 3124, thereby allowing protective surface 3112 of firstelectronic device 3100 to move towards or adjacent to housing 3180 ofsecond electronic device 3160. Second magnet 3170 can be held in placein second electronic device 3160 by housing 3190 or other structure. Assecond electronic device 3160 is removed from first electronic device3100, first magnet 3110 and shield 3140 can be magnetically attracted toreturn plate 3150, as shown in FIG. 31A.

FIGS. 32A and 32B illustrate moving magnetic structures according to anembodiment of the present invention. In this example, first electronicdevice 3200 can be a wireless charger device or other device having afirst magnet 3210 (which can be, e.g., any of the annular or rotationalmagnetic alignment components described herein). FIG. 32A illustrates amoving first magnet 3210 in a first electronic device 3200. Firstelectronic device 3200 can include first magnet 3210, pliable surface3212, housing portions 3220 and 3222, shield 3240, and return plate3250. In this figure, first magnet 3210 is not attracted to a secondmagnet, and therefore shield 3240 is magnetically attached or attractedto return plate 3250. In this position, pliable surface 3212 can berelaxed. Pliable surface 3212 can be formed of an elastomer, siliconrubber open cell foam, silicon rubber, polyurethane foam, or other foamor other compressible material.

In FIG. 32B, second electronic device 3260 has been brought into theproximity of first electronic device 3200. Second magnet 3270 canattract first magnet 3210, thereby causing shield 3240 and return plate3250 to separate from each other. First magnet 3210 can stretch pliablesurface 3212 towards second electronic device 3260, thereby allowingfirst magnet 3210 of first electronic device 3200 to move towardshousing 3280 of second electronic device 3260. Second magnet 3270 can beheld in place in second electronic device 3260 by housing 3290 or otherstructure. As second electronic device 3260 is removed from firstelectronic device 3200, first magnet 3210 and shield 3240 can bemagnetically attracted to return plate 3250 as shown in FIG. 32A.

FIGS. 33-35 illustrate a moving magnetic structure according to anembodiment of the present invention. In this example, first electronicdevice 3300 can be a wireless charger device or other device having afirst magnet 3310 (which can be, e.g., any of the annular or rotationalmagnetic alignment components described herein). In FIG. 33 , firstmagnet 3310 and shield 3340 can be magnetically attracted or attached toreturn plate 3350 in first electronic device 3300. First electronicdevice 3300 can be at least partially housed in device enclosure 3320.In FIG. 34 , housing 3380 of second electronic device 3360 can movelaterally across a surface of device enclosure 3320 of first electronicdevice 3300 in a direction 3385. Second magnet 3370 in second electronicdevice 3360 can begin to attract first magnet 3310 in first electronicdevice 3300. This magnetic attraction 3315 can cause first magnet 3310and shield 3340 to pull away from return plate 3350 by overcoming themagnetic attraction 3345 between shield 3340 and return plate 3350. InFIG. 35 , second magnet 3370 in second electronic device 3360 has becomealigned with first magnet 3310 in first electronic device 3300. Firstmagnet 3310 and shield 3340 have pulled away from return plate 3350thereby reducing the magnetic attraction 3345. First magnet 3310 hasmoved nearby or adjacent to device enclosure 3320, thereby increasingthe magnetic attraction 3315 to second magnet 3370 in second electronicdevice 3360.

As shown in FIGS. 33-35 , the magnetic attraction between first magnet3310 in first electronic device 3300 and the second magnet 3370 in thesecond electronic device 3360 can increase when first magnet 3310 andshield 3340 pull away from return plate 3350. This is shown graphicallyin the following figures.

FIG. 36 illustrates a normal force between a first magnet in firstelectronic device and a second magnet in a second electronic device as afunction of a lateral offset between them. As shown in FIGS. 33-36 ,with a large offset between first magnet 3310 and second magnet 3570,first magnet 3310 and shield 3340 can remain attached to return plate3350 in first electronic device 3300 and the magnetic attraction 3315can be minimal. The shear force necessary to overcome this magneticattraction is illustrated here as curve 3610. As shown in FIG. 34 , asthe offset or lateral distance between first magnet 3310 and secondmagnet 3370 decreases, first magnet 3310 and shield 3340 can pull awayor separate from return plate 3350, thereby increasing the magneticattraction 3315 between first magnet 3310 and second magnet 3370. Thisis illustrated here as discontinuity 3620. As shown in FIG. 35 , asfirst magnet 3310 and second magnet 3370 come into alignment, themagnetic attraction 3315 increases along curve 3630 to a maximum 3640.The difference between curve 3610 and curve 3630 can show the increasein magnetic attraction between a phone or other electronic device, suchas second electronic device 3360, and an attachable wireless chargingdevice or other accessory device, such as first electronic device 3300,that results from first magnet 3310 being able to move axially. Itshould also be noted that in this example first magnet 3310 does notmove in a lateral direction, though in other examples it is capable ofsuch movement. Where first magnet 3310 is capable of moving in a lateraldirection, curve 3630 can have a flattened peak from an offset of zeroto an offset that can be overcome by a range of possible lateralmovement of first magnet 3310.

FIG. 37 illustrates a sheer force between a first magnet in a firstelectronic device and a second magnet in a second electronic device as afunction of a lateral offset between them. With no offset between firstmagnet 3310 and second magnet 3360, there it is no shear force to movesecond magnet 3370 relative to first magnet 3310, as shown in FIG. 33 .As the offset is increased, the shear force, that is the forceattempting to realign the magnets, can increase along curve 3740. Atdiscontinuity 3710, first magnet 3310 and shield 3340 can return toreturn plate 3350 (as shown in FIGS. 33-42 ), thereby decreasing themagnetic shear force to point 3720. The magnetic sheer force cancontinue to drop off along curve 3730 as the offset increases. Thedifference between curve 3730 and curve 3740 can show the increase inmagnetic attraction between a phone or other electronic device, such assecond electronic device 3360 and an attachable wireless charging deviceor other accessory device, such as first electronic device 3300, thatresults from first magnet 3310 being able to move axially. It shouldalso be noted that in this example first magnet 3310 does not move in alateral direction, though in other examples it is capable of suchmovement. Where first magnet 3310 is capable of moving in a lateraldirection, curve 3730 can remain at zero until the lateral movement ofthe second magnet 3370 overcomes the range of possible lateral movementof first magnet 3310.

In these and other embodiments of the present invention, it can bedesirable to further increase this sheer force. Accordingly, embodimentsof the present invention can provide various high friction or highstiction surfaces, suction cups, pins, or other structures to increasethis sheer force. Examples are shown in the following figures.

FIGS. 38A and 38B illustrate a moving magnet in conjunction with a highfriction or high stiction surface according to an embodiment of thepresent invention. In this example, first electronic device 3800 can bea wireless charger device or other device having a first magnet 3810(which can be, e.g., any of the annular magnetic alignment componentsdescribed above). In FIG. 38A, first magnet 3810 and shield 3840 can bemagnetically attracted or attached to return plate 3850 in firstelectronic device 3800. First electronic device 3800 can be housed indevice enclosure 3820. Some or all of a surface of device enclosure 3820can have a coating, layer, or other structure 3822. Structure 3822 canprovide a high friction or high stiction surface. In FIG. 38B, firstmagnet 3810 and shield 3840 can be attracted to a second magnet (notshown) in a second electronic device (not shown). As before, theseparation of first magnet 3810 and shield 3840 from return plate 3850can provide an increased amount of magnetic flux to hold the secondelectronic device in place relative to first electronic device 3800.Structure 3822 can increase the friction or stiction between firstelectronic device 3800 and the second electronic device in a lateral orshear direction.

FIGS. 39A and 39B illustrate a moving magnet in conjunction with a highfriction or high stiction surface according to an embodiment of thepresent invention. In this example, first electronic device 3900 can bea wireless charger device or other device having a first magnet 3910(which can be, e.g., any of the annular or rotational magnetic alignmentcomponents described herein). In FIG. 39A, first magnet 3910 and shield3940 can be magnetically attracted or attached to return plate 3950 infirst electronic device 3900. First electronic device 3900 can be housedin device enclosure 3920. Some or all of a surface of device enclosure3920 can have a coating, layer, or other structure 3922, in this exampleover first magnet 3910. Structure 3922 can provide a high friction orhigh stiction surface. In FIG. 39B, first magnet 3910 and shield 3940can be attracted to a second magnet (not shown) in a second electronicdevice (not shown.) This can cause first magnet 3910 and shield 3940 toseparate from return plate 3850, thereby deforming structure 3922, whichcan be pliable or compliant. As before, first magnet 3910 can provide anincreased amount of magnetic flux to hold the second electronic devicein place relative to first electronic device 3900. Structure 3922 canincrease the friction or stiction between first electronic device 3900and the second electronic device in a lateral or sheer direction.

FIGS. 40A and 40B illustrate a moving magnet in conjunction with a highfriction surface according to an embodiment of the present invention. Inthis example, first electronic device 4000 can be a wireless chargerdevice or other device having a first magnet 4010 (which can be, e.g.,any of the primary annular magnetic alignment components describedabove). In FIG. 40A, first magnet 4010 and shield 4040 can bemagnetically attracted or attached to return plate 4050 in firstelectronic device 4000. First electronic device 4000 can be housed indevice enclosure 4020. Some or all of a surface of device enclosure 4020can have a coating, layer, or other structure 4022, in this example overa top surface of first electronic device 4000. Structure 4022 canprovide a high friction or high stiction surface. In FIG. 40B, firstmagnet 4010 and shield 4040 can be attracted to a second magnet (notshown) in a second electronic device (not shown.) The separation offirst magnet 4010 and shield 4040 from return plate 4050 can push thetop surface formed by structure 4022 upward where it can engage thesecond electronic device with a high-friction surface. As before, firstmagnet 4010 can provide an increased amount of magnetic flux to hold thesecond electronic device in place relative to first electronic device4000. Structure 4022 can increase the friction or stiction between firstelectronic device 4000 and the second electronic device in a lateral orsheer direction.

FIGS. 41A and 41B illustrate another moving magnet in conjunction with ahigh friction or high stiction surface according to an embodiment of thepresent invention. In this example, first electronic device 4100 can bea wireless charger device or other device having a first magnet 4110(which can be, e.g., any of the annular magnetic alignment componentsdescribed above). In FIG. 41A, first magnet 4110 and first shield 4150can be fixed in place in device enclosure 4120 of first electronicdevice 4100. Some or all of a surface of device enclosure 4120 can havea coating, layer, or other structure 4122. Structure 4122 can provide ahigh friction or high stiction surface. First electronic device 4100 canfurther include a moving second magnet 4191 and second shield 4192,which can be attached to sliding mechanism 4190. In FIG. 41B, as asecond electronic device (not shown) comes into contact with firstelectronic device 4100, sliding mechanism 4190 can be depressed, therebymoving second magnet 4191 away from second shield 4192 and the topsurface of device enclosure 4120. The polarity of second magnet 4191 canbe in opposition to, or the opposite of, the polarity of first magnet4110, such that the net magnetic flux at a top surface of deviceenclosure 4120 is increased as sliding mechanism 4190 is depressed.Structure 4122 can increase the friction or stiction between firstelectronic device 4100 and the second electronic device in a lateral orsheer direction.

FIG. 43 is a partially transparent view of the moving magnet structureof FIG. 42 . First electronic device 4200 can be housed in deviceenclosure 4220. As before, first electronic device 4200 can includeinductive charging, near field communication complements, or otherelectronic circuits for components 4278. Return plates 4250 (shown inFIG. 42 ) can be attached to beams 4270.

FIG. 44 is another cutaway side view of the electronic device of FIG. 42. First electronic device 4200 can be housed in device enclosure 4220.As before, first electronic device 4200 can include inductive charging,near field communication components, or other electronic circuits forcomponents 4278. Return plates 4250 can be attached to beams 4270. Firstmagnets 4210 and shield 4240 can be attracted or attached to returnplate 4250. A high friction or high stiction structure 4222 can coversome or all of a top surface of first electronic device 4200. Beams 4270can be attached to return plates 4250, can be anchored at points 4274,and can have a tip 4272 extending above top surface of device enclosure4220.

FIGS. 45 and 46 illustrate the electronic device of FIG. 42 as itengages with a second electronic device. In FIG. 45 , second electronicdevice 4280 can include second magnets 4290. Second electronic device4280 can engage with first electronic device 4200. First electronicdevice 4200 can include first magnets 4210, shields 4240, and returnplates 4250. Return plates 4250 can be attached to beams 4270. Beams4270 can include tips 4272 which can extend above a top surface ofdevice enclosure 4220. Tips 4272 can prevent second electronic device4280 from engaging with the high friction or high stiction structure4222 of first electronic device 4200 until the second electronic device4280 is aligned, or nearly aligned, with first electronic device 4200.Beams 4270 can be attached at points 4274 to device enclosure 4220.First electronic device 4200 can include components 4278.

In FIG. 46 , second electronic device 4280 can be aligned with the firstelectronic device 4200. When this occurs, first magnets 4210 and shields4240 can detach from return plates 4250. This can increase magnetic fluxbetween second magnets 4290 in second electronic device 4280 and firstmagnets 4210 and first electronic device 4200. Tips 4272 can becomedepressed into device enclosure 4220 due to this increase magneticattraction, thereby further pushing return plates 4250 away from shields4240. High friction or high stiction structure 4222 can engage withsecond electronic device 4280 to increase the shear force necessary fora detachment of second electronic device 4280 from first electronicdevice 4200.

In these and other embodiments of the present invention, variousstructures can be used to constrain movement of magnets in an electronicdevice. Examples are shown in the following figures.

FIGS. 47A and 47B illustrate structures for constraining motions ofmagnets in an electronic device according to an embodiment of thepresent invention. In this example, first electronic device 4700 can bea wireless charger device or other device having a first magnet 4710(which can be, e.g., any of the annular magnetic alignment componentsdescribed above). In FIG. 47A, magnet 4710, shield 4740, and structure4770 can be housed by device enclosure 4720 in electronic device 4700.Structure 4770 can include notch 4772, which can fit in tab 4724. InFIG. 47B, magnet 4710 has moved, taking along with it shield 4740 andstructure 4770. Notch 4772 accepts tab 4724 as shield 4740 detaches fromreturn plate 4750. This can constrain the motion of magnets 4710 inelectronic device 4700. Electronic device 4700 can include a top deviceenclosure portion 4722. Tab 4724 can be formed as part of or separatefrom top device enclosure portion 4722.

FIGS. 48A and 48B illustrate structures for constraining motions ofmagnets in an electronic device according to an embodiment of thepresent invention. In this example, first electronic device 4800 can bea wireless charger device or other device having a first magnet 4810(which can be, e.g., any of the annular magnetic alignment componentsdescribed above). In FIG. 48A, magnet 4810, shield 4840, and returnplate 4850 can be housed in device enclosure 4820 of electronic device4800. Top device enclosure portion 4822 can include guide 4824. Guide4824 can constrain motion of magnet 4810 in electronic device 4800. InFIG. 48B, magnet 4810 and shield 4840 have detached from return plate4850 and have been guided into position by guide 4824. Guide 4824 caninclude one or more chamfered edges 4825. Again, guide 4824 can beformed along with or separate from top device enclosure portion 4822 ofelectronic device 4800.

FIGS. 49A and 49B illustrate structures for constraining motions ofmagnets in an electronic device according to an embodiment of thepresent invention. In this example, first electronic device 4900 can bea wireless charger device or other device having a first magnet 3010(which can be, e.g., any of the annular magnetic alignment componentsdescribed above). In FIG. 49A, magnet 4910, shield 4940, and returnplate 4950 can be housed in device enclosure 4920 of electronic device4900. Magnet 4910 and shield 4940 can be supported by structure 4970.Structure 4970 can be attached to anchor 4974 through actuators 4972.Actuators 4972 can have hinges 4973 and 4975 at each end to allowstructure 4970 to move relative to anchor 4974. Anchor 4974 can beattached to, or formed as either part of, top device enclosure portion4922 or device enclosure 4920. In FIG. 49B, magnet 4910 and shield 4940have detached from return plate 4950. Actuators 4972 have changedpositions but continued to connect structure 4970 to anchor 4974. Anchor4974 can be attached to, or formed as either part of, top deviceenclosure portion 4922 or device enclosure 4920.

5. Additional Embodiments

While the invention has been described with reference to specificembodiments, those skilled in the art will appreciate that variationsand modifications are possible. For instance, although the annularalignment modules are described as being made from arcuate magnets thatform sectors, it will be understood that if the magnets are sufficientlysmall relative to the dimensions of the annular structure, trapezoidalor square magnets can approximate the behavior of arcuate magnets.Magnetic alignment components can have any dimensions, and annularmagnetic alignment components can be used with or without rotationalalignment. Magnetic alignment components can be used with an inductivecharging coil to facilitate alignment of the coils as described above,or a magnetic alignment component can be present in a device that doesnot have an inductive charging coil. Further, a portable electronicdevice that has a magnetic alignment component around an inductivecharging coil can be charged by a wireless charger device that does nothave a magnetic alignment component, and conversely, a wireless chargerdevice that has a magnetic alignment component can be used to charge aportable electronic device that has an inductive charging coil but not amagnetic alignment component. In these situations, the magneticalignment component may not facilitate alignment between the devices,but it need not interfere with wireless power transfer.

In addition, while a portable electronic device has been described asreceiving power wirelessly, those skilled in the art will appreciatethat an inductive power coil may be operable to transmit as well asreceive power wirelessly, and in some embodiments a portable electronicdevice can be reconfigurable to operate either as a transmitter orreceiver for wireless power transfer.

Further, while it is contemplated that magnetic alignment components ofthe kind described herein can be used to facilitate alignment betweentransmitter and receiver coils for wireless power transfer betweendevices, use of magnetic alignment components is not so limited, andmagnetic alignment components can be used in a variety of contexts tohold one device in relative alignment with another, regardless ofwhether either or both devices have wireless charging coils. Thus, forinstance, a tripod (or other type of stand), which can hold a portableelectronic device in a particular positon and orientation, can include aprimary annular magnetic alignment component (and a rotational alignmentcomponent) to hold the portable electronic device in place; the magneticalignment component can be used in addition to or instead of mechanicalretention features to secure the portable electronic device to thetripod.

Accordingly, ecosystems of devices are contemplated. The ecosystem caninclude a variety of portable electronic devices having various formfactors, such as smart phones, tablets, or other devices that canoperate on battery power and can receive power via wireless powertransfer. The ecosystem can also include a variety of wireless chargerdevices such as pucks, mats, docks, or the like. The ecosystem can alsoinclude “charge-through” accessories (such as cases) that may beinterposed between a portable electronic device and a wireless chargerdevice; the charge-through accessory is designed to permit magnetic fluxto pass through the interposed portion of the accessory to allowwireless charging while the accessory is present. In such an ecosystem,each portable electronic device can be manufactured to include asecondary annular magnetic alignment component (e.g., having a radial ortransverse magnetic orientation as described above) having dimensions ofradial width and outer diameter that are constant across the ecosystem.Each wireless charger device can be manufactured to include a primaryannular magnetic alignment component complementary to the secondaryannular magnetic alignment components of the portable electronic devices(e.g., having a quad-pole configuration as described above), allowingwireless charger devices to be used interchangeably with differentportable electronic devices. Each charge-through accessory can bemanufactured to include an auxiliary annular magnetic alignmentcomponent complementary to the primary and secondary annular magneticalignment components, again allowing interchangeable use of wirelesscharger devices with different charge-through accessories (and portableelectronic devices).

Such ecosystems can also include other passive accessory devices (i.e.,accessory devices that do not include inductive charging coils) that maybe designed to attach to a portable electronic device using magneticalignment components but that do not support charge-through operation.Examples include tripods or other stands, attachable accessory casesthat may hold credit cards or other magnetized items that may besusceptible to demagnetization during wireless power transfer, or otheraccessories that are intended for use with a portable electronic devicethat is not being charged. Such accessory devices can be manufactured toinclude either a secondary annular magnetic alignment component or anauxiliary annular magnetic alignment component and may or may notinclude a rotational alignment component.

Such ecosystems can also include a “retrofitting” accessory device thatmay be used to provide magnetic alignment capability for a portableelectronic device that was originally manufactured without a magneticalignment component. A retrofitting accessory can have one or moremechanical retention features (e.g., sides and lips of a case shaped asa tray) that hold the smart phone (or other portable electronic device)in a fixed relative alignment with the housing of the accessory. Theaccessory can include a secondary magnetic alignment component (matchingthe specifications of the secondary alignment component for theecosystem), and the secondary magnetic alignment component can bepositioned in the retrofitting accessory so that when the portableelectronic device is held in place by the mechanical retentionfeature(s), the inductive charging coil is centered within the secondarymagnetic alignment component. Such an accessory can allow a portableelectronic device that was manufactured without a magnetic alignmentcomponent to enjoy the benefits of magnetic alignment when used withdevices in the magnetic alignment ecosystem.

It should be understood that, within a given ecosystem, any or all ofthe devices that include annular alignment components may also includerotational alignment components as described above. For instance, withinan ecosystem, all portable electronic devices having a secondary annularalignment component that are large enough to accommodate a rotationalalignment component outboard of the secondary annular alignmentcomponent can have a rotational alignment component. Devices having aprimary alignment component or auxiliary alignment component might ormight not have a rotational alignment component, depending on formfactor and intended use.

It should also be understood that some devices may include multipleannular alignment components. For instance, a wireless charger devicemay be designed with two or more separate wireless charging coils spacedapart from each other to allow multiple portable electronic devices tobe charged at the same time. Each wireless charging coil can have asurrounding primary annular alignment component, and each primaryalignment component can have an associated rotational alignmentcomponent.

In some embodiments, an alignment module that includes an annularalignment component can be packaged for easy installation into anaccessory device, wireless charger device, or portable electronicdevice. For example, an alignment module can include a primary,secondary, or auxiliary annular magnetic alignment component asdescribed above in an enclosing structure (or housing) that protects themagnets and holds them in position In some embodiments, a rotationalmagnetic alignment component can be included along with the annularmagnetic alignment component. The enclosing structure can be, forinstance, a plastic structure, at least part of which can betransparent. As another example, the alignment module can include awireless charging coil (e.g., a transmitter coil) centered within theannular alignment component. The enclosing structure can provide exposedelectrical contacts for making electrical connections to the wirelesscharging coil. Such alignment modules can be made by one entity and soldto a different entity to incorporate into devices such as cases,wireless charging docks, or the like.

Various features described herein related to detection of devices andexchange of information can be realized using any combination ofdedicated components and/or programmable processors and/or otherprogrammable devices. The various processes described herein can beimplemented on the same processor or different processors in anycombination. Where components are described as being configured toperform certain operations, such configuration can be accomplished,e.g., by designing electronic circuits to perform the operation, byprogramming programmable electronic circuits (such as microprocessors)to perform the operation, or any combination thereof. Further, while theembodiments described above may make reference to specific hardware andsoftware components, those skilled in the art will appreciate thatdifferent combinations of hardware and/or software components may alsobe used and that particular operations described as being implemented inhardware might also be implemented in software or vice versa. Computerprograms incorporating various features described herein may be encodedand stored on various computer readable storage media; suitable mediainclude magnetic disk or tape, optical storage media such as compactdisk (CD) or DVD (digital versatile disk), flash memory, and othernon-transitory media. Computer readable media encoded with the programcode may be packaged with a compatible electronic device, or the programcode may be provided separately from electronic devices (e.g., viaInternet download or as a separately packaged computer-readable storagemedium). Further, in regard to any collection or exchange of informationor data by or between devices, it is well understood that the use ofpersonally identifiable information should follow privacy policies andpractices that are generally recognized as meeting or exceeding industryor governmental requirements for maintaining the privacy of users. Inparticular, personally identifiable information data should be managedand handled so as to minimize risks of unintentional or unauthorizedaccess or use, and the nature of authorized use should be clearlyindicated to users.

Embodiments of the invention include but are not limited to any of thefollowing.

In some embodiments, an electronic device (e.g., a portable electronicdevice) can comprise: a housing having an interface surface; aninductive coil disposed within the housing and having an axis normal tothe interface surface, the inductive coil being configured to transferpower wirelessly through the interface surface; and an annular magneticalignment component disposed within the housing coaxial with andoutboard of the inductive coil. The annular magnetic alignment componentcan have a magnetic orientation in a radial direction. The annularmagnetic alignment component can comprise a plurality of arcuatemagnets, and each of the arcuate magnets can have a magnetic polaritythat is oriented in a radially inward (or radially outward) direction.The annular magnetic alignment component can include a gap, and anelectrically conductive path connected to the inductive coil can passthrough the gap. The annular magnetic alignment component can include afirst gap and a second gap on opposite sides of the annular magneticalignment component. A battery can be disposed within the housing, andthe inductive coil can be coupled to the battery. The inductive coil canbe configured to receive and/or transmit power wirelessly through theinterface surface.

In some embodiments, an electronic device (e.g., a wireless chargerdevice) can comprise: a housing having a charging surface; an inductivecoil disposed within the housing and having an axis normal to thecharging surface, the inductive coil being configured to transfer powerwirelessly through the charging surface; and an annular magneticalignment component disposed within the housing coaxial with andoutboard of the inductive coil. The annular magnetic alignment componentcan comprise: an inner arcuate region having a magnetic polarityoriented in a first axial direction; an outer arcuate region having amagnetic polarity oriented in a second axial direction opposite thefirst axial direction; and a non-magnetized central arcuate regiondisposed between the inner arcuate region and the outer arcuate region.The annular magnetic alignment component can comprise a plurality ofarcuate magnets, and each arcuate magnet can have a first region with amagnetic polarity oriented in the first axial direction, a second regionwith a magnetic polarity oriented in the second axial direction, and anon-magnetized region between the first region and the second region.The annular magnetic alignment component can include a gap, and anelectrically conductive path connected to the inductive coil can passthrough the gap. The inductive coil can be configured to transmit and/orreceive power wirelessly through the charging surface.

In some embodiments, an accessory for use with a portable electronicdevice can comprise: a housing having a first interface surface and asecond interface surface opposite the first interface surface; anannular magnetic alignment component disposed within the housing andhaving an axis normal to the first interface surface and the secondinterface surface. The annular magnetic alignment component cancomprise: an inner arcuate region having a magnetic polarity oriented ina first axial direction; an outer arcuate region having a magneticpolarity oriented in a second axial direction opposite the first axialdirection; and a non-magnetized central arcuate region disposed betweenthe inner arcuate region and the outer arcuate region. The annularmagnetic alignment component can comprise a plurality of arcuatemagnets. Each arcuate magnet can have a first region with a magneticpolarity oriented in the first axial direction, a second region with amagnetic polarity oriented in the second axial direction, and anon-magnetized region between the first region and the second region.The annular magnetic alignment component can include a gap. The annularmagnetic alignment component can include a first gap and a second gap onopposite sides of the annular magnetic alignment component.

In some embodiments, a magnetic alignment system can comprise: a primaryalignment component formed of a plurality of primary arcuate magnetsarranged in an annular configuration defining an axis and a secondaryalignment component formed of a plurality of secondary arcuate magnetsarranged in an annular configuration. Each primary arcuate magnet cancomprise: a primary inner arcuate magnetic region having a magneticorientation in a first direction along the axis; a primary outer arcuatemagnetic region having a magnetic orientation in a second directionopposite the first direction; and a non-magnetized primary centralarcuate region disposed between the primary inner arcuate region and theprimary outer arcuate region. Each secondary arcuate magnet having amagnetic orientation that is in a radial direction with respect to acenter of the secondary alignment component. The primary alignmentcomponent can be disposed in a first electronic device surrounding afirst inductive charging coil, and the secondary alignment component canbe disposed in a second electronic device surrounding a second inductivecharging coil; when the primary alignment component and the secondaryalignment component are aligned along a common axis, the first inductivecharging coil and the second inductive charging coil can be also alignedalong the common axis.

In some embodiments, an electronic device (e.g., a portable electronicdevice) can comprise: a housing having an interface surface; aninductive coil disposed within the housing and having an axis normal tothe interface surface, the inductive coil being configured to transferpower wirelessly through the interface surface; an annular magneticalignment component disposed within the housing coaxial with andoutboard of the inductive coil, the annular magnetic alignment componenthaving a magnetic orientation in a radial direction; and a rotationalalignment component comprising a magnet disposed outside an outerperimeter of the annular magnetic alignment component. The rotationalalignment component can comprises a magnet having at least two differentregions of opposing magnetic orientations. In these and otherembodiments, the magnet can have a rectangular shape in a planetransverse to an axis defined by the annular magnetic alignmentcomponent. For example, the at least two different regions of opposingmagnetic orientations can include: a first region extending along afirst long side of the rectangular shape and having a first magneticorientation; and a second region extending along a second long side ofthe rectangular shape and having a second magnetic orientation oppositethe first magnetic orientation. As another example, the at least twodifferent regions of opposing magnetic orientations can include: a firstregion extending along a first long side of the rectangular shape andhaving a first magnetic orientation; a second region extending along asecond long side of the rectangular shape and having the first magneticorientation; and a third region extending along the rectangular shapeand positioned midway between the first region and the second region,the third region having a second magnetic orientation opposite the firstmagnetic orientation. In these and other embodiments, the annularmagnetic alignment component can comprise a plurality of arcuatemagnets, each having a magnetic polarity that is oriented in a radiallyinward direction. In these and other embodiments, a battery can bedisposed within the housing, and the inductive coil can be coupled tothe battery. In these and other embodiments, the inductive coil can beconfigured to receive and/or transmit power wirelessly through theinterface surface.

In some embodiments, an electronic device (e.g., a wireless chargerdevice) can comprise: a housing having a charging surface; an inductivecoil disposed within the housing and having an axis normal to thecharging surface, the inductive coil being configured to transfer powerwirelessly through the charging surface; an annular magnetic alignmentcomponent disposed within the housing coaxial with and outboard of theinductive coil; and a rotational alignment component comprising a magnetdisposed outside a perimeter of the annular magnetic alignmentcomponent. In these and other embodiments, the annular magneticalignment component can comprise: an inner arcuate region having amagnetic polarity oriented in a first axial direction; an outer arcuateregion having a magnetic polarity oriented in a second axial directionopposite the first axial direction; and a non-magnetized central arcuateregion disposed between the inner arcuate region and the outer arcuateregion. In these and other embodiments, the rotational alignmentcomponent can comprise a magnet having at least two different regions ofopposing magnetic orientations. For example, the magnet can have arectangular shape in a plane transverse to an axis defined by theannular magnetic alignment component, and the at least two differentregions of opposing magnetic orientations can include: a first regionextending along a first long side of the rectangular shape and having afirst magnetic orientation; and a second region extending along a secondlong side of the rectangular shape and having a second magneticorientation opposite the first magnetic orientation. As another example,the magnet can have a rectangular shape in a plane transverse to an axisdefined by the annular magnetic alignment component, and the at leasttwo different regions of opposing magnetic orientations can include: afirst region extending along a first long side of the rectangular shapeand having a first magnetic orientation; a second region extending alonga second long side of the rectangular shape and having the firstmagnetic orientation; and a third region extending along the rectangularshape and positioned midway between the first region and the secondregion, the third region having a second magnetic orientation oppositethe first magnetic orientation. In these and other embodiments, theannular magnetic alignment component can comprise a plurality of arcuatemagnets. Each arcuate magnet can have a first region with a magneticpolarity oriented in the first axial direction, a second region with amagnetic polarity oriented in the second axial direction, and anon-magnetized region between the first region and the second region. Inthese and other embodiments, the inductive coil can be configured totransmit power wirelessly through the charging surface.

In some embodiments, an accessory for use with a portable electronicdevice can comprise: a housing having a first interface surface and asecond interface surface opposite the first interface surface; anannular magnetic alignment component disposed within the housing andhaving an axis normal to the first interface surface and the secondinterface surface; and a rotational alignment component comprising amagnet disposed outside a perimeter of the annular magnetic alignmentcomponent. In these and other embodiments, the annular magneticalignment component can comprise: an inner arcuate region having amagnetic polarity oriented in a first axial direction; an outer arcuateregion having a magnetic polarity oriented in a second axial directionopposite the first axial direction; and a non-magnetized central arcuateregion disposed between the inner arcuate region and the outer arcuateregion. In these and other embodiments, the rotational alignmentcomponent comprises a magnet having at least two different regions ofopposing magnetic orientations. For example, the magnet can have arectangular shape in a plane transverse to an axis defined by theannular magnetic alignment component, and the at least two differentregions of opposing magnetic orientations can include: a first regionextending along a first long side of the rectangular shape and having afirst magnetic orientation; and a second region extending along a secondlong side of the rectangular shape and having a second magneticorientation opposite the first magnetic orientation. As another example,the magnet can have a rectangular shape in a plane transverse to an axisdefined by the annular magnetic alignment component, and the at leasttwo different regions of opposing magnetic orientations can include: afirst region extending along a first long side of the rectangular shapeand having a first magnetic orientation; a second region extending alonga second long side of the rectangular shape and having the firstmagnetic orientation; and a third region extending along the rectangularshape and positioned midway between the first region and the secondregion, the third region having a second magnetic orientation oppositethe first magnetic orientation. In these and other embodiments, theannular magnetic alignment component can comprise a plurality of arcuatemagnets. Each arcuate magnet can have a first region with a magneticpolarity oriented in the first axial direction, a second region with amagnetic polarity oriented in the second axial direction, and anon-magnetized region between the first region and the second region.

Accordingly, although the invention has been described with respect tospecific embodiments, it will be appreciated that the invention isintended to cover all modifications and equivalents within the scope ofthe following claims.

What is claimed is:
 1. An accessory device comprising: a housing havinga first interface surface; and an annular magnetic alignment componentdisposed within the housing and having an axis normal to the firstinterface surface, the annular magnetic alignment component including:an inner annular region having a magnetic polarity oriented in a firstaxial direction; an outer annular region having a magnetic polarityoriented in a second axial direction opposite the first axial direction;and a non-magnetized central annular region disposed between the innerarcuate region and the outer arcuate region, wherein a region inboard ofthe annular magnetic alignment component is filled with a material thatis transparent to a time-varying magnetic flux passing through the firstinterface surface.
 2. The accessory device of claim 1 wherein thehousing of the accessory is shaped as a protective case for an activeelectronic device and wherein the annular magnetic alignment componentis positioned such that, when the active electronic device is placed inthe protective case, the region inboard of the annular magneticalignment component aligns with an inductive charging coil of the activeelectronic device.
 3. The accessory device of claim 1 wherein thehousing of the accessory has a second interface surface parallel to thefirst interface surface and wherein the annular magnetic alignmentcomponent is positioned to align along the axial direction with a firstinductive charging coil of a first electronic device placed adjacent tothe first interface surface and with a second inductive charging coil ofa second electronic device placed adjacent to the second interfacesurface.
 4. The accessory device of claim 1 further comprising: arotational alignment component comprising an additional magnet disposedwithin the housing outside a perimeter of the annular magnetic alignmentcomponent.
 5. The accessory device of claim 4 wherein the additionalmagnet has at least two different regions of opposing magneticorientations.
 6. The accessory device of claim 5 wherein the additionalmagnet has a rectangular shape in a plane transverse to the axis andwherein the at least two different regions of opposing magneticorientations include: a first region extending along a first long sideof the rectangular shape and having a first magnetic orientation; and asecond region extending along a second long side of the rectangularshape and having a second magnetic orientation opposite the firstmagnetic orientation.
 7. The accessory device of claim 5 wherein theadditional magnet has a rectangular shape in a plane transverse to theaxis and wherein the at least two different regions of opposing magneticorientations include: a first region extending along a first long sideof the rectangular shape and having a first magnetic orientation; asecond region extending along a second long side of the rectangularshape and having the first magnetic orientation; and a third regionextending along the rectangular shape and positioned midway between thefirst region and the second region, the third region having a secondmagnetic orientation opposite the first magnetic orientation.
 8. Anaccessory device comprising: a housing having a first interface surfaceand a second interface surface opposite the first interface surface; anannular magnetic alignment component disposed within the housing andhaving an axis normal to the first interface surface and the secondinterface surface, the annular magnetic alignment component including:an inner annular region having a magnetic polarity oriented in a firstaxial direction; an outer annular region having a magnetic polarityoriented in a second axial direction opposite the first axial direction;and a non-magnetized central annular region disposed between the innerarcuate region and the outer arcuate region; and a block of magneticmaterial positioned inboard of the annular magnetic alignment componentto guide an externally-produced time-varying magnetic flux between thefirst interface surface and the second interface surface.
 9. Theaccessory device of claim 8 wherein the housing of the accessory isshaped to hold an active electronic device and wherein the annularmagnetic alignment component is positioned such that, when the activeelectronic device is held by the housing, the block of magnetic materialpositioned inboard of the annular magnetic alignment component alignswith an inductive charging coil of the active electronic device.
 10. Theaccessory device of claim 8 wherein the housing of the accessory has asecond interface surface parallel to the first interface surface andwherein the annular magnetic alignment component is positioned to alignalong the axial direction with a first inductive charging coil of afirst electronic device placed adjacent to the first interface surfaceand with a second inductive charging coil of a second electronic deviceplaced adjacent to the second interface surface.
 11. The accessorydevice of claim 8 further comprising: a rotational alignment componentcomprising an additional magnet disposed within the housing outside aperimeter of the annular magnetic alignment component.
 12. The accessorydevice of claim 11 wherein the additional magnet has at least twodifferent regions of opposing magnetic orientations.
 13. The accessorydevice of claim 12 wherein the additional magnet has a rectangular shapein a plane transverse to the axis and wherein the at least two differentregions of opposing magnetic orientations include: a first regionextending along a first long side of the rectangular shape and having afirst magnetic orientation; and a second region extending along a secondlong side of the rectangular shape and having a second magneticorientation opposite the first magnetic orientation.
 14. The accessorydevice of claim 12 wherein the additional magnet has a rectangular shapein a plane transverse to the axis and wherein the at least two differentregions of opposing magnetic orientations include: a first regionextending along a first long side of the rectangular shape and having afirst magnetic orientation; a second region extending along a secondlong side of the rectangular shape and having the first magneticorientation; and a third region extending along the rectangular shapeand positioned midway between the first region and the second region,the third region having a second magnetic orientation opposite the firstmagnetic orientation.
 15. An accessory device comprising: a housinghaving a first interface surface and a second interface surface oppositethe first interface surface; an annular magnetic alignment componentdisposed within the housing and having an axis normal to the firstinterface surface and the second interface surface, the annular magneticalignment component including: an inner annular region having a magneticpolarity oriented in a first axial direction; an outer annular regionhaving a magnetic polarity oriented in a second axial direction oppositethe first axial direction; and a non-magnetized central annular regiondisposed between the inner arcuate region and the outer arcuate region;a first inductive coil inboard of and coaxial with the annular magneticalignment component and proximate to the first interface surface; and asecond inductive coil inboard of and coaxial with the annular magneticalignment component and proximate to the second interface surface, thesecond inductive coil axially spaced apart from and electrically coupledto the first inductive coil.
 16. The accessory device of claim 15further comprising: a rotational alignment component comprising anadditional magnet disposed within the housing outside a perimeter of theannular magnetic alignment component.
 17. The accessory device of claim16 wherein the additional magnet has at least two different regions ofopposing magnetic orientations.
 18. The accessory device of claim 17wherein the additional magnet has a rectangular shape in a planetransverse to the axis and wherein the at least two different regions ofopposing magnetic orientations include: a first region extending along afirst long side of the rectangular shape and having a first magneticorientation; and a second region extending along a second long side ofthe rectangular shape and having a second magnetic orientation oppositethe first magnetic orientation.
 19. The accessory device of claim 17wherein the additional magnet has a rectangular shape in a planetransverse to the axis and wherein the at least two different regions ofopposing magnetic orientations include: a first region extending along afirst long side of the rectangular shape and having a first magneticorientation; a second region extending along a second long side of therectangular shape and having the first magnetic orientation; and a thirdregion extending along the rectangular shape and positioned midwaybetween the first region and the second region, the third region havinga second magnetic orientation opposite the first magnetic orientation.20. The accessory device of claim 15 wherein the annular magneticalignment component is positioned to align the first inductive chargingcoil with a transmitter coil of a first electronic device placedadjacent to the first interface surface and with a receiver coil of asecond electronic device placed adjacent to the second interfacesurface.